Where is the extra 150W coming from?

actually its only about 1.5 amps more.  A 55 amp alternator doesnt sound
like it has much room for slop. Maybe it does...  but that 14 amp number you
have is wrong. maybe a decimal got lost in the translation.

   As long as the circuit is fused, then there should be no problem..... if
you are drawing more than yo ushould, the fuse will blow and you may want to
consider piggybacking off another circuit that doesn't require as much
amperage, or use a blank circuit and put in its own fuse.

good Luck...

Fwed

So, how much are you drawing during idle with the headlights on?  From
this, you can figure the idle load on the alternator.  Be sure to turn
all the other accessories on when you measure it.

Even so, I would be much more worried about the headlight wiring harnesses
and overheating the lamps than I would about the alternator.  But measure
it and see!
--scott

The auxiliary lights would normally use a 55W bulb, as would the
headlights, so the extra draw should be 110 Watts. If the draw is
too great for the alternator, then the alternator may overheat (and
smell hot), it likely will make a whining noise, and the lights will
dim noticeably when the engine speed drops to idle. The risk is that
you wear out the alternator or drain the battery. The risk increases
if you are in slow moving traffic or are using the rear window
defroster, wipers, etc.

That said, I have never heard of a problem with adding a pair of
auxiliary lights to a modern car.
Dan

(This account is not used for email.)

Hmm, 2x55w = 110w, and 2x35w = 70w. Not sure where you get your 150w?
Anyway, no, those extra headlights should not be a problem if you wire
them correctly.

Ulf

Most times that I see folks upgrading to 'high output' headlights in
older vehicles, they fast burn out the headlight switch.  I would
physically try to 'gently' grab the headlight switch looking for heat.
If it is hot, then you should wire a bosch style relay in with it's own
10 ga. fused power line direct to the battery and only use the headlight
switch to trigger the low amp side of the relay.

You could be amazed at how white your lights become.  I was when I did
mine.

The same goes for the auxiliary lights.  If you want the headlight
switch to run those too (like for extra highbeams) you need a relay for
sure.

You also need to pay attention to the ground path.  I added an extra
ground cable for the extra load a new fan and lights put on the existing
body ground.  The ground can be too small and/or they get corroded
connections and forgotten about often.

When I added two 100 watt Hella Black Magic driving lights into my 86
Jeep with it's 65 amp alternator, I added a massive GM heater blower fan
motor at the same time.  I turned on everything in the vehicle and ran
it for a while, then felt the alternator for heat.  I already checked it
running normal and the added lights and fan didn't make a difference.
The volt gauge also didn't seem to react any difference.

You also need to pay attention to the ground path.  I added an extra
ground cable for the extra load a new fan and lights put on the existing
body ground.  The ground can be too small and/or they get corroded
connections and forgotten about often.

My alternator is now about 6 years old.  Kits can be had for most of the
old ones fairly cheap.

Here is a site on wiring a Bosch style relay.
http://www.classictruckshop.com/clubs/earlyburbs/projects/bosch/relay.htm

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos:  Non members can still view!
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I think you're okay as you are -- 150 watts at 12 V is 12 A.

Seldom will the car be all the way up to its alternator capacity of 55
A.  It's worth thinking about because in the winter you're more often
running a few to several power-hungry accessories at once (headlights,
defroster or heater with its blower motor, wipers...) and perhaps are
more likely to be sitting in traffic at idle, where your alternator is
not making its full output, though it's still better than the
old-fashioned generator under those circumstances.

When this happens the car is essentially running from the battery.
Ammeters tell this tale directly by sagging a bit to the negative side,
though of course you can infer it from voltmeters.  (It has to be
pretty gloomy to trigger an idiot light.)  When you pick up a little
speed the ammeter swings to the positive side for  a while as the
alternator pays back the battery.

Anyway, if you're not scaring its full capacity I wouldn't worry.  What
you don't want to do is go into the winter with extra loads and a dodgy
battery, so make sure it's in good shape and has nice clean solid
connections.

As for overloading switches or whatnot... operate them with an
aftermarket relay, and a *fused* line from the battery to said relay.
Parts and kits are pretty readily available these days because of the
popularity of both auxiliary lights and large trunk-mounted stereo
equipment.

Cheers,
--Joe

PS.  You didn't mention whether you are configuring these as proper
DRLs or manually controlling them with a separate switch.  I assume
that by "auxiliary driving lights" you mean the ones that are like
extra high beams, rather than fog lights.  Especially in the former
case, be sure to turn them off at night when there is oncoming traffic.
  And don't make the opposite mistake either, of failing to turn on
your "real" headlights (and thus taillights too) in dark or rain, just
because you have a DRL-like accessory.  Not that YOU'D make either of
those mistakes, of course, but since so many drivers do, and one never
knows who's going to read these postings,  I thought I'd mention it.

You are probably okay with the lights, as long as you wire the auxillary
lights up properly, but you should take a look at the total continuous
electrical load you are likely to run before deciding to kick in the
extra lights. This includes the rest of the lights, ECU/Ignition,
electric cooling fan if it has one, Blower motor/AC, wipers, rear window
defogger, plus any fancy stereo equipment it might have.

 I found my 65 amp alternator on my F-150 could not keep up with
auxillary lights and a power amp for the stereo, especially at night
with the A/C blower on medium or high. I can also remember another time
I might have fried an alternator on my '78 Horizon when it started
raining. On came the lights, rear window defogger, and defrosters, while
the radio played on. The ammeter never worked well on that car, so I
didn't know about the dead battery that was about to cause my car to
grind to a  halt until the dashboard went nuts and the engine started
misfiring.