robcarnut

I have been experiencing periodic battery drain which is inconsistent, but extremely irritating. Dealership is currently getting a .01 ohms draw under current situations. Battery will eventually get a draw down that will require a jump start. The battery, starter, alternator are all new and work properly. The car has a new ignition switch installed by the dealership.

Has anyone had a short that they had to repair-where was it located? I am trying to suggest to the mechanic where to first look at the wiring harness in a particular area that periodically is grounding out, causing the battery to draw down.

One thought was that a relay was coming on periodically causing a power draw. Which one, who knows.

Seeking any suggestions for what appears to be an electrical gremlin!!
rob


Have two 2000 Firebirds for my twin 18 year olds, 1998 Z28 is the old man's-mine

Injuneer

An "Ohm" is not a current draw. Did you mean 0.01 amps? If so, that's not enough to drain the battery.... normal for fractions of an amp required to maintain memory in radio, PCM, etc.

robcarnut

You are correct, amp draw.

Any suggestions on possible draw locations?
Radio amp, courtesy light and drivers seat motor I've found through the various threads. These are all goods leads. I am trying to give the mechanic some possible locations to check on. Currently the short/draw is not surfacing while he is testing the circuits.

Injuneer

This is getting confused, because of your duplicate post in another thread. See response there on how to find the current draw.

My input to the other thread:

GaryDoug

The map light switches are vulnerable to shorting.

robcarnut

There is the normal "micro" current draw (amps) that is taking place, which he says is not causing the battery to draw down to the point of not being able to engage the starter. He can not determine which circuit is the cause for "large" drawdown because when he checks the tester, the normal "micro" parameters are occurring. The battery cables are New, not corroded, as well as the battery, alternator, starter and ignition switch.
This is a sporadic occurrence. I've been able to drive this car with no issues for a week or two every day, then the next day come out to start the car to find the battery has been drained.
I am trying to isolate a higher probability location where a drain could be occurring that others have had, for the mechanic to inspect. He has spoken to others and with the other items that I've listed, he also said that the accelerator pedal on another car had caused a similar result.
The mechanic is a career GM mechanic, over age 50, who has a second generation Camaro that he restored. He rebuilds transmissions and upper blocks at the dealership and is given the harder jobs to deal with.
He does not want to go down the path of remove/replace components, he is trying to isolate the cause, but since it is a sporadic occurrence, it has not surfaced.
My kids wants to drive the car now that the weather is getting better so anyway to provide a "top ten" list of most probable electrical problem area could perhaps lead us to the cause.

GaryDoug

Is this car one of the Firebirds? If so, the problem might be with the headlight door control module shorting. It has power all the time. It is located beside the most forward of the two underhood fuse/relay boxes. To test it over a long period of time, raise the headlamps and unplug the 5-wire connector at the module. That will isolate the module and leave the headlights up and usable. There might be water inside that can cause leakage like you are seeing. Open it up and look for water or burnt components. Also check for water or corrosion under the connectors.

robcarnut

GaryDoug,

Thanks. We did replace the headlamp control module as well as both headlight motors, the motors had failed within the last year. The mechanic came up with the suggestion for the headlight module, but this did not eliminate the problem. You are the 3rd person who mention the module, so it was a good suggestion to check.

My own humble opinion is either the stereo amp or the body control module. Both components get warmed up after the car has been driven, and perhaps don't shut down entirely when the car gets shutoff during those odd times that the malfunctioning component wants to act up. The BDM is $325 cost at the dealership, no idea for the stereo amp. I want to replace the stereo anyway with a new head unit and all the speakers, which will require a full rewire because its the infamous Monsoon system. Perhaps at that time, the gm amp could be pulled.

GaryDoug

I would start pulling fuses one or two at a time whenever you leave the car and see if or when the problem disappears. Keep a list of the fuses you have already tried. And keep a spare battery in the back;-)

If you really want to narrow this down, get one of those clamp meters that measure DC current using the clamp. Then when the battery goes dead, use the meter to measure the drain current while you pull fuses one-at-as time. Make sure the clamp part measures DC current not just AC.

I have this one and it works fine:
My review: http://www.firebirdnation.com/forums...mp-multimeter/