Hi everyone,

I've been trying to figure this out for a couple of weeks and not having much luck.

A few weeks ago the car wasn't driven for a few days and the battery died (-20 to -30C weather here). Bought a new battery but this also died within a day or two. More recently a headlamp went (though I'm surprised these ones have lasted so long!).

Amp draw when everything is off is 100 milliamps - thinking there much be a drain somewhere. Pulled fuses and found fuse 24 in j/b fusebox lowered to 20-30 milliamps. Also found that pulling the rear wiper fuse lowered the draw by about 20milliamps. Then found out my girlfriend had tried to use the rear wiper when it was frozen and it ground to a halt, and now doesn't work - seems like the motor may have burnt out. However, pulling the harness for the rear wiper didn't lower the amp drain at all.

Also pulled a few harnesses on fuse 24: rear defogger, headlamp battery saver unit, few others. I found that pulling the harness to the headlamp battery saver unit lowered the drain to about 35 milliamps, but then went straight back up and I haven't been able to replicate it.

I pulled fuse 24 and left the car overnight (15 hours). Battery was reading 12.6v when I left it, but next morning was 11.8 and wouldn't turn the engine.

I'm now thinking there may be a diode issue in the alternator. All voltage drop tests are good on both positive and negative sides between the battery and alternator. However AC across the battery with the engine running gives about 30 volts - but I think this may be an issue with my cheap meter - 30 volts AC sounds way too high to me. Otherwise the alternator seems to be charging the battery well and it doesn't discharge when disconnected.

So I'm stumped. Would an additional draw of 20millamps ( from the rear wiper?) be enough to drain a fully charged brand new battery overnight (though it has been cold)? Or does this sound like a diode issue? Or something else I've not thought of. Would really appreciate anyone's thoughts!

Thanks!

Jon

Do you have a CEL?

Do you have any codes present?

That small of a current draw is not going to kill your battery that quickly. I would look for the most likely culprit. Your car is 19 years old so do you know if your alternator has ever been replaced? I just replaced mine for the first time six months ago.