> Includes headlights;...
That was a very important piece of information that you have left out.
> ...I was guessing voltage regulation, but maybe not.
>
> Will check the feeds and grounds.
OK - listen very carefully - lest you think I am casually making guesses
as to the cause of your problem, I speak as the owner of two Concordes
that are the same car electrically. I have experienced and solved the
*exact* problem. I have seen the same problem reported on the LH
car-specific forums - and the almost always turns out to be one of the
following:
(1) A corroded/loose connection at the battery
(2) A loose connection at the positive jump post
(3) A loose ground (AKA negative jump post on passenger side strut tower).
Most likely it is (2). That junction carries *ALL* power for the
vehicle with the exception of the hot wire to the alternator. It is a
stud with three cables clamped on a stud - one cable from the battery,
one cable to the starter, one cable to *EVERYTHING* else (lights, dash,
radio, etc.). A loose nut on that stud means poor clamping (high
resistance, large voltage drop, lots of heat) of the cable terminals to
each other. Symptoms can be ecxactly what you have reported, or starter
intermittently not working, or the two occurring randomly as the quality
of the connection among the three cables changes with temperature,
vibration, phase of the moon...
Be aware that the nuts on the stud may *seem* tight, but if they have
been loose for a while, the threads can get heated, galled, and lightly
welded to the stud, and *appear* tight when actually they are loose
(i.e., not clamping the cable terminals, but the nuts don't turn because
the threads are arced together from heat and electrical arcing). To be
sure they are actually tight (i.e., actually clamping the terminals and
not just binding threads), back one of the nuts off (either one - to
break the threads loose), and then *re-tighten* with torque on the high
end of reasonable.
NOTE: Careful when wrenching the nuts on the positive jump post stud -
if your wrench touches any surrounding metal (ground) while it is on
those nuts (direct connection to battery +12V), you will have lots of
sparks, and possible damage or injury - it would be best to disconnect
the ground post while working on that.
But also check (1) and (3) as they have been known to be the cause of
the same problem.
> Thanks, and Happy New Year.
You're welcome - same to you.
Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')
AirBoss - 31 Dec 2006 19:35 GMT
> > Includes headlights;...
>
[quoted text clipped - 49 lines]
>
> Bill Putney
Appears to have been (1), although I wonder why all of a sudden, other
than a quick temperature swing. Will continue to check the other 2
psbl causes.
Thanks again.
Ken Weitzel - 31 Dec 2006 19:38 GMT
>> Includes headlights;...
>
[quoted text clipped - 43 lines]
> But also check (1) and (3) as they have been known to be the cause of
> the same problem.
Hi...
My turn to add to your thoughts, Bill :)
Disconnect completely the battery negative, then and only then work on
the positive post and mid-point connections. Put the battery negative
back as the last step in your repairs, and voila! Virtually zero risk
of a slipped wrench or dropped tool or piece of jewelery shorting anything.
And I'd not only check for tightness, I'd suggest taking 'em apart, then
polishing things up with a wire brush or piece of sandpaper until
they're nice and shiny.
Finally, I'd do it now, before it really starts to cost you. If the
voltage is varying enough that you can see it in the headlights, it
won't be long before you're replacing light bulbs, the radio, the
computers, and whatever else that really doesn't like the rapid on/off
sequencing.
My usual disclaimer; not a mechanic, just an old retired electrical guy.
Take care.
Ken
Bill Putney - 31 Dec 2006 20:24 GMT
> Hi...
>
[quoted text clipped - 4 lines]
> back as the last step in your repairs, and voila! Virtually zero risk
> of a slipped wrench or dropped tool or piece of jewelery shorting anything.
Good advice. However, disconnecting the negative ground point
(passenger side jump post) effectively accomplishes that without having
to access the buried battery (PITA). (Couldn't let you one-up me!!
Just kidding - neither one of us looks at it that way.)
> And I'd not only check for tightness, I'd suggest taking 'em apart, then
> polishing things up with a wire brush or piece of sandpaper until
> they're nice and shiny.
Good point.
> Finally, I'd do it now, before it really starts to cost you. If the
> voltage is varying enough that you can see it in the headlights, it
[quoted text clipped - 7 lines]
>
> Ken
Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')