 |
 | Home | Contact Us | FAQ | Search & Site Map | Link to Us |
 | Sign In | Join | Other 45 Sites in Network |
Car Forum / Honda Cars / November 2007Why you should remove the negative battery terminal before doing ANYTHING!!!!
I was lokking thorugh the Subaru manual to find out where the thermostat was. I'm used to it being on TOP of the engine. While it ididn't show the location, it did say, "Remove negative battery terminal, and remove thermostat housing..." Huh? Remove the - terminal berfore removing the thermostat housing?! WTF?!?! Last night I went to pick up my papers for my "paper route" and saw a big-a.s GMC pickup I hadn't seen before. Then I saw one of my firend's fathers, who started doing the papers about 10 days after I did. He usually drive an '01 Pathfinder. "Where's the Pathfinder?" "I wrecked it." "WHAT?!?!?!?!" Well, he didn't really wreck it. He had a bad bulb in the overhead light. He removed the lens, and the bulb was in pieces, but still working intermittantly. He removed the bulb and replaced the lens, and then tried to start the truck. No Go. The starter spins, but the engine doesn't catch. Looks like he fried the ECU!!!! All the other lights work, the dome light works, but the fuel pumpo doesn't energize. He tried the reset procedure and nothing. I had heard of this before; I can't remember what the car was, but someone shorted out the ECU replacing the dome light... > I was lokking thorugh the Subaru manual to find out where the thermostat > was. I'm used to it being on TOP of the engine. [quoted text clipped - 22 lines] > I had heard of this before; I can't remember what the car was, but someone > shorted out the ECU replacing the dome light... Typical dome light bulb is a dual contact base, he may have caused a momentary short circuit to ground removing the broken bulb. Sounds far-fetched, but possible that that could have damaged something. nate  Signaturereplace "roosters" with "cox" to reply. http://members.cox.net/njnagel Hachiroku wrote: <snip crap> > I had heard of this before; I can't remember what the car was, but someone > shorted out the ECU replacing the dome light... no way - the ecu's not even connected to the dome light. and they're electrically protected against all kinds of "user error", including battery reversal, over-voltage, dead shorts and static. short of direct lightning strike, water damage, or fire, none of which have a single damned thing to do with dome lights, the ecu's not going anywhere and it's /certainly/ not going to be fubared by a bulb change. > Hachiroku wrote: > <snip crap> [quoted text clipped - 9 lines] > damned thing to do with dome lights, the ecu's not going anywhere and > it's /certainly/ not going to be fubared by a bulb change. Hi, No way? If short caused a surge in the electrical system, anything is possible. In cases like this mostly nothing serious happens but result unpredictable. Protection is not absolute 100%. >> Hachiroku wrote: >> <snip crap> [quoted text clipped - 13 lines] > possible. In cases like this mostly nothing serious happens but result > unpredictable. Protection is not absolute 100%. Bullshit!! >>>Hachiroku wrote: >>><snip crap> [quoted text clipped - 16 lines] > > Bullshit!! Hmmm, Live little longer and gain some more experience! >>>>Hachiroku wrote: >>>><snip crap> [quoted text clipped - 19 lines] >Hmmm, >Live little longer and gain some more experience! It's still bullshit. Maybe you could make up a scenereo where someone unhooked all the grounds from the ECU, removed it from its metal support brakets and insulated it and then wired it directly to the dome light circuit but supporting such myths as changing a dome light bulb f.cked up an ECU is assanine. Signaturegburnore at DataBasix dot Com --------------------------------------------------------------------------- How you look depends on where you go. --------------------------------------------------------------------------- Gary L. Burnore | ÝÛ³ºÝ³Þ³ºÝ³³Ýۺݳ޳ºÝ³Ý³Þ³ºÝ³ÝÝÛ³ | ÝÛ³ºÝ³Þ³ºÝ³³Ýۺݳ޳ºÝ³Ý³Þ³ºÝ³ÝÝÛ³ Official .sig, Accept no substitutes. | ÝÛ³ºÝ³Þ³ºÝ³³Ýۺݳ޳ºÝ³Ý³Þ³ºÝ³ÝÝÛ³ | ÝÛ 0 1 7 2 3 / Ý³Þ 3 7 4 9 3 0 Û³ Black Helicopter Repair Services, Ltd.| Official Proof of Purchase =========================================================================== >> Hachiroku wrote: >> <snip crap> [quoted text clipped - 11 lines] > Hi, > No way? If short caused a surge in the electrical system, short won't cause voltage surge. measure the voltage across a battery as you increase current load - voltage goes down, not up. only other potential source of surge is back emf from relays, motors, etc, and they're all diode/condenser protected, as is the ecu. bottom line: it's not the dome light. > anything is > possible. yeah, it could have been hit by meteorite. > In cases like this mostly nothing serious happens but result > unpredictable. Protection is not absolute 100%. yeah, it could have been hit by meteorite. >>> Hachiroku wrote: >>> <snip crap> [quoted text clipped - 27 lines] > > yeah, it could have been hit by meteorite. hmmm, Whatever you think. A car battery has lots of energy in it. Think current in this case. >>>> Hachiroku wrote: >>>> <snip crap> [quoted text clipped - 31 lines] > Whatever you think. A car battery has lots of energy in it. > Think current in this case. do what i said - measure voltage as a function of load. then report your results. >>>>> Hachiroku wrote: >>>>> <snip crap> [quoted text clipped - 35 lines] > do what i said - measure voltage as a function of load. then report > your results. Hmmm, No, current as a function of load! Do you remember the days of generators under the automobile hoods? >>>>>> Hachiroku wrote: >>>>>> <snip crap> [quoted text clipped - 37 lines] > Hmmm, > No, current as a function of load! electrical current /is/ load... take any battery, then measure the voltage as you increase current load on it. then let us know what happens. and how you think high current [short] can cause a "surge". > Do you remember the days of > generators under the automobile hoods? why? have any basic laws of physics changed since then? >>>>>>> Hachiroku wrote: >>>>>>> <snip crap> [quoted text clipped - 48 lines] > > why? have any basic laws of physics changed since then? No. Some times in real world things happen where basic law has difficulty to explain how and why. First thing I learned about generator when I was a kid was polarizing. > >>>>>>> Hachiroku wrote: > >>>>>>> <snip crap> [quoted text clipped - 52 lines] > difficulty to explain how and why. > First thing I learned about generator when I was a kid was polarizing. trim posts >> >>>>>>> Hachiroku wrote: >> >>>>>>> <snip crap> [quoted text clipped - 54 lines] > >trim posts ok. Signaturegburnore at DataBasix dot Com --------------------------------------------------------------------------- How you look depends on where you go. --------------------------------------------------------------------------- Gary L. Burnore | ÝÛ³ºÝ³Þ³ºÝ³³Ýۺݳ޳ºÝ³Ý³Þ³ºÝ³ÝÝÛ³ | ÝÛ³ºÝ³Þ³ºÝ³³Ýۺݳ޳ºÝ³Ý³Þ³ºÝ³ÝÝÛ³ Official .sig, Accept no substitutes. | ÝÛ³ºÝ³Þ³ºÝ³³Ýۺݳ޳ºÝ³Ý³Þ³ºÝ³ÝÝÛ³ | ÝÛ 0 1 7 2 3 / Ý³Þ 3 7 4 9 3 0 Û³ Black Helicopter Repair Services, Ltd.| Official Proof of Purchase =========================================================================== In article <fh7hl0$qvl$5@blackhelicopter.databasix.com>, Gary L. Burnore <gburnore@databasix.com> wrote very little but quoted way, way, way too much. As he always does, apparently. Gary L. Burnore doesn't know how to trim posts. >>>>>>>> Hachiroku wrote: >>>>>>>> <snip crap> [quoted text clipped - 51 lines] > No. Some times in real world things happen where basic law has > difficulty to explain how and why. bull - that is a function of insufficient learning by the observer. > First thing I learned about generator when I was a kid was polarizing. polarizing is not surge! >>>>>>>> Hachiroku wrote: >>>>>>>> <snip crap> [quoted text clipped - 52 lines] >difficulty to explain how and why. >First thing I learned about generator when I was a kid was polarizing. What does that have to do with a car that doesn't contain a generator? What does that have to do with something supposedly related to a battery? Why aren't you answering his questions or providing results of the tests that would prove your "surge" claim invalid? Signaturegburnore at DataBasix dot Com --------------------------------------------------------------------------- How you look depends on where you go. --------------------------------------------------------------------------- Gary L. Burnore | ÝÛ³ºÝ³Þ³ºÝ³³Ýۺݳ޳ºÝ³Ý³Þ³ºÝ³ÝÝÛ³ | ÝÛ³ºÝ³Þ³ºÝ³³Ýۺݳ޳ºÝ³Ý³Þ³ºÝ³ÝÝÛ³ Official .sig, Accept no substitutes. | ÝÛ³ºÝ³Þ³ºÝ³³Ýۺݳ޳ºÝ³Ý³Þ³ºÝ³ÝÝÛ³ | ÝÛ 0 1 7 2 3 / Ý³Þ 3 7 4 9 3 0 Û³ Black Helicopter Repair Services, Ltd.| Official Proof of Purchase =========================================================================== >>>>>> Hachiroku wrote: >>>>>> <snip crap> [quoted text clipped - 38 lines] >No, current as a function of load! Do you remember the days of >generators under the automobile hoods? I do, and there weren't ECUs then. Basing your argument on something that is now non-existant is very telling. Signaturegburnore at DataBasix dot Com --------------------------------------------------------------------------- How you look depends on where you go. --------------------------------------------------------------------------- Gary L. Burnore | ÝÛ³ºÝ³Þ³ºÝ³³Ýۺݳ޳ºÝ³Ý³Þ³ºÝ³ÝÝÛ³ | ÝÛ³ºÝ³Þ³ºÝ³³Ýۺݳ޳ºÝ³Ý³Þ³ºÝ³ÝÝÛ³ Official .sig, Accept no substitutes. | ÝÛ³ºÝ³Þ³ºÝ³³Ýۺݳ޳ºÝ³Ý³Þ³ºÝ³ÝÝÛ³ | ÝÛ 0 1 7 2 3 / Ý³Þ 3 7 4 9 3 0 Û³ Black Helicopter Repair Services, Ltd.| Official Proof of Purchase =========================================================================== >>>> Hachiroku wrote: >>>> <snip crap> [quoted text clipped - 29 lines] >hmmm, >Whatever you think. A car battery has lots of energy in it. A short won't cause a voltage surge. >Think current in this case. You might want to try starting with just plain thinking. Signaturegburnore at DataBasix dot Com --------------------------------------------------------------------------- How you look depends on where you go. --------------------------------------------------------------------------- Gary L. Burnore | ÝÛ³ºÝ³Þ³ºÝ³³Ýۺݳ޳ºÝ³Ý³Þ³ºÝ³ÝÝÛ³ | ÝÛ³ºÝ³Þ³ºÝ³³Ýۺݳ޳ºÝ³Ý³Þ³ºÝ³ÝÝÛ³ Official .sig, Accept no substitutes. | ÝÛ³ºÝ³Þ³ºÝ³³Ýۺݳ޳ºÝ³Ý³Þ³ºÝ³ÝÝÛ³ | ÝÛ 0 1 7 2 3 / Ý³Þ 3 7 4 9 3 0 Û³ Black Helicopter Repair Services, Ltd.| Official Proof of Purchase =========================================================================== >Whatever you think. A car battery has lots of energy in it. >Think current in this case. You are utterly without a clue. Best keep quiet. >> yeah, it could have been hit by meteorite. > > hmmm, > Whatever you think. A car battery has lots of energy in it. > Think current in this case. Think "fuse" in this case.... unless it was one of those Chinese-made fuses from Harbor Freight... ;-) >> Hachiroku wrote: >> <snip crap> [quoted text clipped - 11 lines] >Hi, >No way? If short caused a surge in the electrical system, You're kidding right? Signaturegburnore at DataBasix dot Com --------------------------------------------------------------------------- How you look depends on where you go. --------------------------------------------------------------------------- Gary L. Burnore | ÝÛ³ºÝ³Þ³ºÝ³³Ýۺݳ޳ºÝ³Ý³Þ³ºÝ³ÝÝÛ³ | ÝÛ³ºÝ³Þ³ºÝ³³Ýۺݳ޳ºÝ³Ý³Þ³ºÝ³ÝÝÛ³ Official .sig, Accept no substitutes. | ÝÛ³ºÝ³Þ³ºÝ³³Ýۺݳ޳ºÝ³Ý³Þ³ºÝ³ÝÝÛ³ | ÝÛ 0 1 7 2 3 / Ý³Þ 3 7 4 9 3 0 Û³ Black Helicopter Repair Services, Ltd.| Official Proof of Purchase =========================================================================== >>>Hachiroku wrote: >>><snip crap> [quoted text clipped - 14 lines] > > You're kidding right? Hi, Probably you don't even know basic Ohm's law or Kirchoff's or Tevnin Norton's theorem, etc. If you want to debate, email me directly. Let's compare our CV first. >>>> Hachiroku wrote: >>>> <snip crap> [quoted text clipped - 19 lines] > Tevnin Norton's theorem, etc. If you want to debate, email me directly. > Let's compare our CV first. tony, this is usenet - "credentials" don't mean sh.t. just stick to the facts. fact 1 - batteries don't "surge". period. some [reactive] peripherals can do it, unless protected. in cars, they all are. dome lights are not reactive. fact 2 - ohmic behavior dictates that battery voltage drops as current increases, not the other way around. fact 3 - ecu's are "idiot proofed". per #1, a dome light has no reaction that could possibly cause a problem, even if the ecu was unprotected. conclusion: either address reality or move on. > tony, this is usenet - "credentials" don't mean sh.t. just stick to the > facts. > > fact 1 - batteries don't "surge". period. some [reactive] peripherals > can do it, unless protected. in cars, they all are. dome lights are > not reactive. No but a direct short could cause a problem in the item shorted. In the case of some vehicles that could be the BCM if they use it for things like an interior light timer/dimmer (close door and dome light stays on for a bit) Shorting that circuit cause problems. > fact 2 - ohmic behavior dictates that battery voltage drops as current > increases, not the other way around. Yes BUT take a chunk of wire and toss it across the battery. Measure the battery voltage. It likely won't cause a voltage drop as it heats up and melts. > fact 3 - ecu's are "idiot proofed". per #1, a dome light has no > reaction that could possibly cause a problem, even if the ecu was > unprotected. VERY WRONG. ECUs are easy to kill if you are not paying attention. My SOP in the body shop is to pull the ECU on anything that rolls in for panel work. One good zap from a welder can kill the ECU without being near it. > conclusion: either address reality or move on. SignatureSteve W. Near Cooperstown, New York NRA Member Pacifism - The theory that if they'd fed Jeffrey Dahmer enough human flesh, he'd have become a vegan. jim beam <spamvortex@bad.example.net> wrote; >> fact 2 - ohmic behavior dictates that battery voltage drops as >> current increases, not the other way around. > > Yes BUT take a chunk of wire and toss it across the battery. Measure > the battery voltage. It likely won't cause a voltage drop as it heats > up and melts. Yes,it will.That battery has internal resistance,and a short will draw a lot of current and make for a heavy V drop.(the same happens every time you start your car;there are specs for battery Vdrop while cranking.) SignatureJim Yanik jyanik at kua.net > jim beam <spamvortex@bad.example.net> wrote; > [quoted text clipped - 9 lines] > lot of current and make for a heavy V drop.(the same happens every time you > start your car;there are specs for battery Vdrop while cranking.) Hi, Internal resistance is very small value. Against dead short it's not a big factor. Cranking is not a dead short situation. Once I dropped a pair of plier across heavy industrial battery terminals. The plier litterally evaporated. >> jim beam <spamvortex@bad.example.net> wrote; >> [quoted text clipped - 12 lines] > Hi, > Internal resistance is very small value. what is it then? state the number of ohms. typical honda civic battery. > Against dead short it's not a > big factor. it is when it's the largest resistance in the circuit! > Cranking is not a dead short situation. and? > Once I dropped a > pair of plier across heavy industrial battery terminals. The plier > litterally evaporated. sure. and how much did the voltage drop? >> tony, this is usenet - "credentials" don't mean sh.t. just stick to >> the facts. [quoted text clipped - 7 lines] > like an interior light timer/dimmer (close door and dome light stays on > for a bit) Shorting that circuit cause problems. rubbish. >> fact 2 - ohmic behavior dictates that battery voltage drops as current >> increases, not the other way around. > > Yes BUT take a chunk of wire and toss it across the battery. Measure the > battery voltage. It likely won't cause a voltage drop as it heats up and > melts. "likely"??? dude, it /definitely/ does! grade school science class. >> fact 3 - ecu's are "idiot proofed". per #1, a dome light has no >> reaction that could possibly cause a problem, even if the ecu was [quoted text clipped - 4 lines] > panel work. One good zap from a welder can kill the ECU without being > near it. eh? welding is a whole different ball game to shorting a fuse protected light circuit. welding is done at voltages and currents in excess of those seen in vehicle operation, and is accompanies by all kinds of radio frequency noise, both from the spark and the welder, depending on welder type! yes, it's good to disconnect the ecu while welding. no, shorting a light circuit doesn't replicate those conditions. >> conclusion: either address reality or move on. > > tony, this is usenet - "credentials" don't mean sh.t. just stick to the > > facts. [quoted text clipped - 33 lines] > Jeffrey Dahmer enough human flesh, > he'd have become a vegan. Guys, guys... go get a schematic and find out if the dome light is in the same circut as the ECU. Even if it is, I don't think the changing of the bulb is what caused the problem. I do think that whatever caused the light to function intermittantly MIGHT have cused the ECU problem. Either way, if the light was working sometimes, that would tell me that there was nothing wrong with the bulb. Funny thing about light bulbs... they either work, or they don't. The filament is either complete, or it's not. It doesn't go back once it's blown. Okay, so if there's a short, it would be either in the fixture, or in the wires going to it. Furthermore, That's what fuses are for! I've done it many many times. Shorting things out and blowing fuses and replacing them again. The fuse opens the circut in the event of a short before ANYTHING gets damaged (unless the fuse is either disregarded, or replaced with a fuse of a higher amperage). And furthermore, since we're on the topic of fuses, this is the whole reason that things like dome lights and tail lights and headlights and radios and ESPECIALLY ECU's are all on thier own circuts with thier own fuses. Kind of insurance, if one thing blows a fuse, you don't lose everything at once. I do agree with the titlehead of this issue, being "disconnect the negitive before working". But this rule is mostly in place because sometimes people like to play with the wires and accidently drop the exposed end of a hot wire onto the bare frame of body of the vehicle. The result can be a blown fuse at minimum, or a small fire at most (I've been there, too). However, I regress (and conclude), the dome light bulb cannot be the reason for ECU problems. ECU's may or may not be "idiot proofed," but they are not on the same circut as the dome light, the dome light cannot cause "power surges" and niether can anything else on a vehicle, and even if anything were to happen, the fuses would have caught it. Case Closed. Go get a new ECU, and re-wire your dome light. quit griping about crap that is not relevant. The more you gripe, the more other people despise you, and the job still is not done. On Tue, 13 Nov 2007 04:33:54 +0000, fury45iii wrote: > Guys, guys... go get a schematic and find out if the dome light is in the > same circut as the ECU. Even if it is, I don't think the changing of the [quoted text clipped - 7 lines] > what fuses are for! I've done it many many times. Shorting things out and > blowing fuses and replacing them again. Yeah, but we're talking a Nissan here! I've seenthings in Nissans I've never seen in other cars. And, he said the glass was broken. How it even lit without burning out is a mystery! > On Tue, 13 Nov 2007 04:33:54 +0000, fury45iii wrote: > [quoted text clipped - 16 lines] > And, he said the glass was broken. How it even lit without burning out is > a mystery! First you said that the bulb was in pieces, not that the glass was broken. Was it really broken? I have seen several times that the glass part of a bulb can separate from its socket but still hanging by the leads it may still work. And I have also seen that the ends of a broken lamp filament can dangle together and get get kind of welded together, so it works again, but usually not for long. What may kill an ECU is the very very short transients in voltage when a cirquit somewhere in the system is abruptly opened or closed, especially when it is high current (a short) and/or repeated many times. If he made a momentarily short cirquit while changing the bulb that MAY be enough. That is why with modern cars we are advised not to use jumper cables without transient suppressors. Asbjørn > VERY WRONG. ECUs are easy to kill if you are not paying attention. My > SOP in the body shop is to pull the ECU on anything that rolls in for > panel work. One good zap from a welder can kill the ECU without being > near it. A welder and a dome light are vastly different things. An arc welder generates a HUGE reactive voltage spike when striking the arc, and that spike can wander all over the entire vehicle and fry sensitive electronics and not-so-sensitive things, too, like alternator diodes. Standard procedure there is to disconnect the battery whenever doing any welding on the thing. Shorting a dome light will NOT generate any sort of spike. Period. You need a coil to generate spikes, coils like those found in starters, alternator rotors, ignition coils. You might as well try to generate a spike by disconecting and reconnecting the battery. Dan >>VERY WRONG. ECUs are easy to kill if you are not paying attention. My >>SOP in the body shop is to pull the ECU on anything that rolls in for [quoted text clipped - 13 lines] > > Dan Hmmm, Lamp filament is a tiny coil, LOL! >>> VERY WRONG. ECUs are easy to kill if you are not paying attention. My >>> SOP in the body shop is to pull the ECU on anything that rolls in for [quoted text clipped - 16 lines] > Hmmm, > Lamp filament is a tiny coil, LOL! with an air core and virtually no inductance. if you have instruments that can measure any voltage spike you get from a coiled bulb filament, i'd love to see your readings. >>>> VERY WRONG. ECUs are easy to kill if you are not paying attention. My >>>> SOP in the body shop is to pull the ECU on anything that rolls in for [quoted text clipped - 20 lines] > that can measure any voltage spike you get from a coiled bulb filament, > i'd love to see your readings. Hmmm, You are so bone headed, can't even take a joke. The more you babble, the more you reveal your lack of knowledge: pratical or thory. My job used to deal with fraction of nano amps. VLSI, ASIC, etc. on mil-spec. >>>>> VERY WRONG. ECUs are easy to kill if you are not paying attention. My >>>>> SOP in the body shop is to pull the ECU on anything that rolls in for [quoted text clipped - 25 lines] > pratical or thory. My job used to deal with fraction of nano amps. VLSI, > ASIC, etc. on mil-spec. bullshitting idiot. The very reason that using a wrong bulb: Will set a code on an OBD2 system. RK PS I'm not speculating on Jim's method of earning a living. But there are such instruments available. >>>>>> VERY WRONG. ECUs are easy to kill if you are not paying attention. My >>>>>> SOP in the body shop is to pull the ECU on anything that rolls in for [quoted text clipped - 27 lines] > > bullshitting idiot. > The very reason that using a wrong bulb: > > Will set a code on an OBD2 system. that's load measurement, not inductance from a bulb filament coil. > RK > > PS > I'm not speculating on Jim's method of earning a living. But there are such > instruments available. of course! but i bet t.h. doesn't have any, and i'll bet he doesn't know how to measure whether it has any noticeable effect! >>>>>>> VERY WRONG. ECUs are easy to kill if you are not paying attention. My >>>>>>> SOP in the body shop is to pull the ECU on anything that rolls in for [quoted text clipped - 26 lines] >>> ASIC, etc. on mil-spec. >> bullshitting idiot. >with an air core and virtually no inductance. if you have instruments >that can measure any voltage spike you get from a coiled bulb filament, >i'd love to see your readings. I do. BUT, you don't need one. If you have an 1141 lamp with 50 loops of 1/16" (that's estimated by eye here) about 1/2" long, you can use Wheeler's Formula: 50^2 * (0.065)^2 10.5 --------------- = ----- = 0.27 microhenries 18 * 0.065 + 40 * 0.5 28.0 That's a lot less than the hundreds of henries that an arc welder ballast will have, and it's probably small enough to be compensated for by the capacitance of the wiring, even. But it's enough that you could measure it carefully with a scope and a pulse generator, even though it's actually going to be swamped at any reasonable voltage by the nonlinearity when the filament heats up and its resistance increases. --scott Signature"C'est un Nagra. C'est suisse, et tres, tres precis." >> with an air core and virtually no inductance. if you have instruments >> that can measure any voltage spike you get from a coiled bulb filament, [quoted text clipped - 13 lines] > will have, and it's probably small enough to be compensated for by the > capacitance of the wiring, even. excellent. and it's /well/ below any level that could /possibly/ impact the ecu! > But it's enough that you could measure it > carefully with a scope and a pulse generator, even though it's actually > going to be swamped at any reasonable voltage by the nonlinearity when the > filament heats up and its resistance increases. indeed. > excellent. and it's /well/ below any level that could /possibly/ impact > the ecu! You seem to forget that the dome light is 'live' all the time using a ground as a switch. They can have the glass fall out of the base and the loose internal connecting wire(s) can and will cause a short circuit. This happens all the time with bulbs such as the 1157 in taillights. Short circuits can do nasty things to computers like blow the input diode 'before' the fuse has a chance to blow. It's not like the designers of modern vehicles are just BSing when they say to unhook the negative before working on them..... Mike 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 'New' frame in the works for '08 Hello: This might seem odd to you but, newer cars use bulbs that are a specific impedance. A 2157 is the same candle power as an 1157, but the impedance is higher. That's why if you use a 2157 in place of a 3057 for argument's sake. You'll get a check engine light in an OBD2 compliant vehicle. RK >>>VERY WRONG. ECUs are easy to kill if you are not paying attention. My >>>SOP in the body shop is to pull the ECU on anything that rolls in for [quoted text clipped - 16 lines] > Hmmm, > Lamp filament is a tiny coil, LOL! On about 92 and up: The dome light is connected to the Body Control Module. RK >>>>> Hachiroku wrote: >>>>> <snip crap> [quoted text clipped - 34 lines] > > conclusion: either address reality or move on. > On about 92 and up: > > The dome light is connected to the Body Control Module. > > RK Hey, RK, how ya doin'? I wanted to ask you something a while ago, but I forget. At any rate, right. The DL is connected to the BCM, which MAY have a connection to the ECM. >>>>>> Hachiroku wrote: >>>>>> <snip crap> [quoted text clipped - 35 lines] >> >> conclusion: either address reality or move on. >>On about 92 and up: >> [quoted text clipped - 8 lines] > At any rate, right. The DL is connected to the BCM, which MAY have a > connection to the ECM. Boy, am I glad that my newest vehicle is an '83... JT I'm doing great! Thank you. If anything is connected to the BCM, it will be in someway connected to the ECM. Through a Bus or a connector. RK >> On about 92 and up: >> [quoted text clipped - 48 lines] >>> >>> conclusion: either address reality or move on. > On about 92 and up: > > The dome light is connected to the Body Control Module. yes, which is not the ecu! > RK >>> [quoted text clipped - 34 lines] >> >> conclusion: either address reality or move on. The BCM is always communicating with the ECU! RK >> On about 92 and up: >> [quoted text clipped - 41 lines] >>> >>> conclusion: either address reality or move on. >Tevnin Norton's theorem, etc. If you want to debate, email me directly. Hey, I can even _spell_ Thevenin >No way? If short caused a surge in the electrical system, anything is >possible. Maybe he reversed the polarity of the Bogon Flux ? > Hachiroku wrote: > <snip crap> [quoted text clipped - 7 lines] > damned thing to do with dome lights, the ecu's not going anywhere and it's > /certainly/ not going to be fubared by a bulb change. I talked to him last night. He says he wants you to come out and tell him why his Pathfinder won't start after changing the dome light... On Tue, 13 Nov 2007 02:12:44 GMT, Hachiroku ???? <Trueno@AE86.gts> wrote: >> Hachiroku wrote: >> <snip crap> [quoted text clipped - 10 lines] >I talked to him last night. He says he wants you to come out and tell him >why his Pathfinder won't start after changing the dome light... Anybody that says a short on a voltage line can't hurt an ECU has never worked on computers..... SignatureScott in Florida >>> Hachiroku wrote: >>> <snip crap> [quoted text clipped - 13 lines] > Anybody that says a short on a voltage line can't hurt an ECU has never > worked on computers..... He said there was a spark when he tried to remove the bulb. The bulb's glass was broken, and he tried to grab it without touching anything else, but there was a spark, and when he tried to start the truck...nothing. He had it towed to a Nissan dealer. They're trying to find a used ECU and told him that before doing ANYTHING electrical with the truck he should... disconnect the negative battery terminal... (Next week he's removing the terminal and installing a Negative Terminal Shut-off...) It could be a coincidence? Maybe there is another problem. RK >> Hachiroku wrote: >> <snip crap> [quoted text clipped - 11 lines] > I talked to him last night. He says he wants you to come out and tell him > why his Pathfinder won't start after changing the dome light... > Hachiroku wrote: > <snip crap> [quoted text clipped - 4 lines] > > no way - the ecu's not even connected to the dome light. That much is not true in all cases. Any care that has "theater fade" interior lights, for example, has them powered from a computer module (not necessarily the engine controller, but a "body controller" or some other computer module.) > and they're > electrically protected against all kinds of "user error", including > battery reversal, over-voltage, dead shorts and static. short of direct > lightning strike, water damage, or fire, none of which have a single > damned thing to do with dome lights, the ecu's not going anywhere and > it's /certainly/ not going to be fubared by a bulb change. And on all of THAT, I agree completely! I personally have seen a bunch of blown ECU's caused by wiring shorts, mostly fuel pumps, but other things too. Sure the ECU is 'protected' by a diode, but no one sells the damn diode to replace the blown one nor do many 'authorized' places exist to fix them. Half are sunk in a block of plastic also. I have repaired a few by using a cheap diode with a +/- 10 to 15% tolerance so they fell close to the original specs. Close enough to work. If the dome light is on a timer, it is connected to some kind of computer.... Mike 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 'New' frame in the works for '08 > I was lokking thorugh the Subaru manual to find out where the thermostat > was. I'm used to it being on TOP of the engine. [quoted text clipped - 22 lines] > I had heard of this before; I can't remember what the car was, but someone > shorted out the ECU replacing the dome light... \ > Well, he didn't really wreck it. He had a bad bulb in the overhead light. > He removed the lens, and the bulb was in pieces, but still working [quoted text clipped - 7 lines] > I had heard of this before; I can't remember what the car was, but someone > shorted out the ECU replacing the dome light... I don't buy it. ECUs are actually *very* well protected against intermittent faults, voltage spikes, etc. (Zener diodes are a wonderful thing). 99.9% of the "failed" ECUs people pull out of cars are actually fine and the problem lies elsewhere. There's no WAY you can hurt one just changing a light bulb. |
Reply to this Message |
 Sign In
 Join
 My Latest Posts My Monitored Threads My Blog My Photo Gallery My Profile My Homepage Start New Thread Enable EMail Alerts Rate this Thread
|
©2008 Advenet LLC Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.