Hi folks -

Our 99 A4 coupe is having an issue that I just don't know where to start.

I had a 3 year old Optima red top in the car, and about 2 months ago I went out to start the car and it would not start.

The battery was only putting out 5.6 volts.

I took the battery back to Sams Club and they gave me a new one no questions asked.

I put in the new battery and drove the car with no problems, taking it to Bowling Green, and driving it around town a bit.

I put the car away when the snow started to hit, in a heated garage, and put a battery tender on it - I rotate a battery tender around to my Z06 (which also has a red top - no problems) and my motorcycle batteries.

There was no problem until this week when I got the tender back onto the 99 coupe - and it showed a fault in the battery. The volt meter shows 5.8 volts.

The only thing that I have done to the car in the last year is the following:

added led cove lights
added led footwell lights
added led bulbs in the map lights
added Web Electrics sequential taillight harnesses.

How can I diagnose this issue to determine what is causing the car to eat batteries, or just what the problem is?

best regards -

mqqn

 

Provided your cables are tight and free of corrosion....

You'll need to audit the current draw with a good battery. Bill has the steps documented in the electrical sticky. Start at post #590

http://forums.corvetteforum.com/c5-t...post1567522286

 

Thanks Lucky - heading out to the garage now....



best regards -

mqqn

 

Originally posted by Bill Curlee........

If your seeing 0.020 amps,,,,,something stayed ON and killed the battery.

The most problematic current gobblers are:

Stuck seat multifunction switch
Bose Amp relay
RAP Relay failure
Interior lights

Don't know the best way to troubleshoot a sporadic problem like this one.

BC

 

Hi lucky -

I have the battery out of the car and on a 10 amp charger -

I am going to remove the cheap ebay map light bulbs I bought, and the sequential taillight harnesses and then do the draw test.

I do remember one "funny" thing - when I was putting in the sequential harness, there was corrosion on the factory bulb socket on one side - and when I was testing the harness turning on the turn signals, the dash lights were flashing with the turn signals!

I used a brass brush and cleaned out the factory socket really well and that seemed to have fixed the problem.

I will just ace the sequential harness and make sure that is all cleaned up as a precaution.

The electrics on these cars are spooky.

Thanks a lot for helping me with the links - I appreciate it.

best regards -

mqqn

 

Yep. Troubleshooting an excessive current draw problem can be time consuming due to waiting for the "sleep mode", but you'll figure it out.