Need Diagnosis for Electrical Starting Problem

[smithk3933]

My 01TT with 30k miles is having problems staring. It's like the battery is dead, dash lights come on but just clicks and won't start. I put a charger on it for couple of minutes and it starts OK. Runs fine after. The voltage gauge shows 13 volts. I've run it for a while and next day same thing.

I took it by and Advance Auto and they tested with their meter. Says battery is fine, it's about 1 year old, alternator is showing charging OK. We shut everything off and they said it showed a draw of .9amps. This was with everything off including pulling the light in the front trunk. Does this sound like a normal draw or is this enough to run the battery down so quick?

Looking for ideas before I have to go to the dealer!

Thanks.

Keith

[Sunnyside]

Hi Keith,

Firstly, get the car running and go for a long drive 40 mins to an hour. Give it a good run.

Check the voltage on the dash to start and keep an eye on it. I suspect your alternator voltage rectifier is playing up. Very common fault and if the alternator isn't hot it will look absolutely fine...........until it gets hot. Then the voltage will very slowly start to drop on the dash. May get as low as 10.5V. This is a sure sign the V reg is on its way out. Putting it on a tester machine will not show this defect until the alternator has got hot.

Give it a try.

As to 0.9 amps thats not bad at all, do you have a tracker. After 5 or so days the car will shut down most electrical systems it can automatically. Its a Hibernation mode. So .9 amps doesn't sound too bad considering its not In Hibernation.

Frank

Edited March 2, 2011 by Sunnyside