Traverse 0 Posted January 5, 2011 I've had a battery drain in my '90 G60 for the last six months or so. I didn't change anything in the car before this began. I tried to search but couldn't find any results that helped. I've tested my alternator, swapped batteries, pulled every single relay/fuse out of the car that it didn't need, replaced both battery cables, unhooked the stereo and seatbelts, and nothing has helped it. The only things I haven't done are replace the ignition and the starter. As soon as a second car is hooked up to it, it'll fire right up without any wasted time (seriously, within 1-2min.). I've even tried unhooking the battery while the car is parked, but it didn't work either. I'm about at my wit's end. Both the ignition and starter are relatively expensive, so I'd like to hear what other people have to say before I dive into replacing them. Quote Share this post Link to post Share on other sites
jackvine 0 Posted January 5, 2011 So even when the battery is disconnected the battery is draining? Quote Share this post Link to post Share on other sites
Traverse 0 Posted January 5, 2011 Yes, which would imply something is draining it while the car is running. I tried a new alternator and battery though, so I doubt it would be either of those. Quote Share this post Link to post Share on other sites
davidwort 0 Posted January 5, 2011 so what voltage do you get across the battery with the engine running? Quote Share this post Link to post Share on other sites
RW1 0 Posted January 5, 2011 What is the voltage across from the alternator body to battery earth terminal? (Millivolt reading value) . Quote Share this post Link to post Share on other sites
Supercharged 2 Posted January 5, 2011 Ok, 2 things it could be if the fault is not on one of the fusebox circuits. 1 - aftermarket alarm or imobiliser if fitted 2 - The electric window module behind the rear door card - this runs straight from the battery so can be disconnected easily to test, they seem to go wrong in a way that they start to drain around 10 times as much power as they should. What's the drain? I assume you checked the obvious like the boot light and also pulled relays to test? Quote Share this post Link to post Share on other sites
Traverse 0 Posted January 5, 2011 so what voltage do you get across the battery with the engine running? Around 14v. Ok, 2 things it could be if the fault is not on one of the fusebox circuits. 1 - aftermarket alarm or imobiliser if fitted 2 - The electric window module behind the rear door card - this runs straight from the battery so can be disconnected easily to test, they seem to go wrong in a way that they start to drain around 10 times as much power as they should. What's the drain? I assume you checked the obvious like the boot light and also pulled relays to test? I have no aftermarket alarm or anything like that. My trunk light has always been disconnected, and I also tried pulling relays. I'll check out that window module though, but could you be a little more specific about the location? Thanks for all of the help so far, everyone. Quote Share this post Link to post Share on other sites
Supercharged 2 Posted January 5, 2011 It's behind one of the rear door cards but feeds directly from the battery so you can disconnect that red cable to test - it's roughly 4-5mm thick (red) Quote Share this post Link to post Share on other sites
jackvine 0 Posted January 5, 2011 Have you put a amp metre on it when the engine is off to see what the current is being drawn ? Quote Share this post Link to post Share on other sites
Traverse 0 Posted January 5, 2011 Have you put a amp metre on it when the engine is off to see what the current is being drawn ? Yes, it's just barely below average. I think it reads at about a 12.6 or something. Quote Share this post Link to post Share on other sites
davidwort 0 Posted January 5, 2011 Have you put a amp metre on it when the engine is off to see what the current is being drawn ? Yes, it's just barely below average. I think it reads at about a 12.6 or something. think you have your Amps and Volts confused, current drain with engine off should be arounnd 0.01A IIRC and that's with an immobiliser and live wired (but turned off) head-unit battery should be near 13V when new, 12.5 when older and alternator should maintain about 14V across battery when engine is running, shouldn't drop much with lights, HRW, blower etc., switched on either. Quote Share this post Link to post Share on other sites
jackvine 0 Posted January 5, 2011 12.6 Volts ? You need to do a current reading with the engine off, and see how many amps are being drawn. You can't just put the meter across the battery it needs to be put inline with the positive terminal. Normaly different connections on your multimeter Quote Share this post Link to post Share on other sites
Traverse 0 Posted January 5, 2011 No, you guys were right. I got my volts and amps confused... Thanks for correcting me. I'll go out and check it when I get off work. Quote Share this post Link to post Share on other sites
CorradoVR6-Turbo 0 Posted January 5, 2011 window module is behind the rear drivers side quarter panel,before disconnecting this put your multimeter between the neg side of the battery and set it to amp draw,see what the results are? Quote Share this post Link to post Share on other sites
The_Dude 0 Posted January 5, 2011 window module is behind the rear drivers side quarter panel,before disconnecting this put your multimeter between the neg side of the battery and set it to amp draw,see what the results are? He's in the USA so it will be the passenger side? (on the right if you are sat in the car) Quote Share this post Link to post Share on other sites
CorradoVR6-Turbo 0 Posted January 5, 2011 ah right! um...dont know i would suspect the ns then? :lol: Quote Share this post Link to post Share on other sites
RW1 0 Posted January 5, 2011 Easy enough to determine. With closed windows, just press the window switches for "up". The relays in the unit will be heard from behind one of the rear passenger panels. . Quote Share this post Link to post Share on other sites
Traverse 0 Posted January 5, 2011 Thanks guys, I'll go check it as soon as I get a chance... Probably not until Friday though :( Quote Share this post Link to post Share on other sites
paddywagong60 0 Posted January 8, 2011 im having the same issue Quote Share this post Link to post Share on other sites
ryan_16v 0 Posted January 8, 2011 Try replacing the boot switch, it worked for me. Quote Share this post Link to post Share on other sites
Traverse 0 Posted January 21, 2011 Try replacing the boot switch, it worked for me. Boot switch? Like the light in the trunk? Quote Share this post Link to post Share on other sites
Supercharged 2 Posted January 21, 2011 Try replacing the boot switch, it worked for me. Boot switch? Like the light in the trunk? Yup, easy to test, just take out the parcel shelf... Quote Share this post Link to post Share on other sites
sparks 0 Posted January 22, 2011 i had a simlar problem with an old mini alternator belt was slipping so under full load it didnt put anything into the battery and went flat off load it read 14v and looked fine id try a new belt mate there are cheap enough to buy !! stu ... Quote Share this post Link to post Share on other sites
