Battery draning overnight

**soulstyler** · 20-12-2010,09:27 PM

Recently I have found my battery flat on my diesel B5 estate on monday mornings after using it at the weekend. I then jump start it from the wifes Clio (much to her delight) to get to work but seems ok the rest of the week. I have had the battery tested and seems ok and garage tightend loose terminal connections but still dead in morning. Durring the summer the alarm was going off at strange times so I got a fault read done which said a fault with passenger side locks so I leave it unlocked at night. Could the car being unlocked be the cause as suggested by previous threads, or the faulty locks draining power? Not sure what to do next, is there someway of testing where the powers going or should i go straight to auto-electrician. Any help would be greatly appreciated.

Thanks.

George

Oh, i've also got an aftermarket stereo which has been in for nearly 6 months so not sure this would make a difference?!

**martin1810** · 20-12-2010,09:56 PM

My money is on the stereo. But...Take off negative lead from battery. Connect multimeter set for 200 mA between battery -ve terminal and -ve leadl. See what it reads. Much over 20 mA and you have a drain. Disconnect the meter, remove a fuse, reconnect the meter. Keep swapping out fuses to the drain remains low. DO NOT do anything while the meter is connected. Even opening a door with the meter connected will blow the fuse in the meter.

**jammy86** · 22-12-2010,07:49 PM

Originally Posted by soulstyler

Oh, i've also got an aftermarket stereo which has been in for nearly 6 months so not sure this would make a difference?!

Can you turn your stereo on even when the car is off? My money is that You need to switch the red and yellow wires round on the stereo.

**caldirun** · 22-12-2010,08:58 PM

Originally Posted by soulstyler

Recently I have found my battery flat on my diesel B5 estate on monday mornings after using it at the weekend. I then jump start it from the wifes Clio (much to her delight) to get to work but seems ok the rest of the week. I have had the battery tested and seems ok and garage tightend loose terminal connections but still dead in morning. Durring the summer the alarm was going off at strange times so I got a fault read done which said a fault with passenger side locks so I leave it unlocked at night. Could the car being unlocked be the cause as suggested by previous threads, or the faulty locks draining power? Not sure what to do next, is there someway of testing where the powers going or should i go straight to auto-electrician. Any help would be greatly appreciated.

Thanks.

George

Oh, i've also got an aftermarket stereo which has been in for nearly 6 months so not sure this would make a difference?!

If the battery is over 2 years old change it, there are tests you can do but a 90 Amp hr battery going flat over the weekend would need a serious drain.

**soulstyler** · 22-12-2010,10:25 PM

Originally Posted by jammy86

Can you turn your stereo on even when the car is off? My money is that You need to switch the red and yellow wires round on the stereo.

No, the stereo comes on only when I turn the keys.
I am currently removing the cable from the negative terminal each night to avoid flat battery, will test with fuses soon when getting some free time and less snow.
Glad to hear nobody has suggested it could be leaving it unlocked or a fault in the locks causing the drain, although when I switch the ignition on I can hear the rear passenger lock functioning for a moment.

**jammy86** · 30-12-2010,11:40 PM

I'd still look into the wiring on the stereo and make sure it is correct just to rule it out.

**KieranM** · 05-01-2011,08:00 PM

I have been having this problem on my b5 estate, an auto electrician found that my CCM was floating in water, also that the connection to the actual CCM had some green corrosion on it, which causes resistance which was draining my month old battery.

This in theory, as my CCM is currently drying over a radiator! I will put it back together tomorrow, and will update to see if that solved the issue.

Also if anyone has some advice on how to stop it filling with water (sealing the pollen filter, or even I think my passenger window seal may not be good as it has had electrical tape on it since I bought the car.

There was a link to "how to stop the passenger footwell filling with water" job, but I can't seem to find it.

Thanks and good luck

**Peter D** · 06-01-2011,09:30 AM

Search of Plenum Chamber. The drains holes (2) may be bunged up and the pollen filter seal has perished. Regards Peter

**KieranM** · 06-01-2011,06:32 PM

Thanks, so I put the CCM back in the morning, the black wires (4 into one) were no longer attached, and the yellow wire (4 into one) is corroded. I have cleaned the yellow wires, and I have re soldered the black wires.

Since putting the CCM back, my passenger side front and back windows no longer work, I can hear a clicking inside the door when I press the button but nothing is happening.

I'm guessing I need to check my connections, and re solder the yellow wires.

Thanks.

Kieran