Re: [DML] Re: AC quits working when the car stops moving?

[Andrew <aos+yahoo@xxxx>]

On Wed, 21 May 2003, Harold McElraft wrote:

> If the car voltage drops that much you may have a bad battery or a
> battery that is very run down.

I've charged the battery all the way up several times and tested all the
cells. I've also tried swapping with a known-good battery. It's not
that. Whenever I start with a fully charged battery, I get good voltage
in the system for a while, but then it slowly drops down, eventually to
about 11.5 at idle. (With reasonable driving, though, the battery tends
to stay around 12.5, so it's nearly charged.)

> The alternator could be weak also.

This was my initial thought, particularly since my 20 year old Motorola
was oozing some sticky goop out the bottom. I got a 140 amp replacement
from John Hervey (specialtauto.com) and that hasn't solved the problem.

I met up with John at the DMCH open house and he's letting me borrow a
second 140 amp alternator, so I can be sure something hasn't blown up the
voltage regulator on the first. I have yet to find time to get them
swapped out, but I'll try that soon.

> It could also be that a ground is not good. There is the cable ground
> from the battery of course, then the ground strap at the motor mount,
> and the really troublesome one on the frame going to the central ground
> connection in the connection box in the engine compartment and coming
> out in the car behind the backboard above the relay compartment. The
> positive cable and/or wires could be troubled connections too.

Cleaned every last one of them with sand paper and WD40. This actually
has helped. I'm up probably 2 volts at speed and maybe half a volt at
idle. A definite improvement, but not there yet.

> You will find it eventually. Keep testing.

Still hunting! :)

-andrew
#4115
Houston TX