Battery Drain - Diagnosing

[pj29]

Well, I have picked up a drain on the battery of my '90 convertible that is causing it to discharge in a day or two.

I hadn't encountered this problem until recently. The only thing I've done in the last couple of weeks was installing a MTech I steering wheel in place of the airbag wheel. I did disconnect the airbag sensor so that the light on my check panel wouldn't flash. Anyone encounter that causing a erin on the battery?

Where does everyone start when they encounter this?

Thanks.

[noid]

Well, I have picked up a drain on the battery of my '90 convertible that is causing it to discharge in a day or two.

I hadn't encountered this problem until recently. The only thing I've done in the last couple of weeks was installing a MTech I steering wheel in place of the airbag wheel. I did disconnect the airbag sensor so that the light on my check panel wouldn't flash. Anyone encounter that causing a erin on the battery?

Where does everyone start when they encounter this?

Thanks.

Put a multi meter in line to your negative battery terminal to check drain. Then pull each fuse until you see the drain drop, that way you know the drain is coming from that circuit.

[pj29]

Put a multi meter in line to your negative battery terminal to check drain. Then pull each fuse until you see the drain drop, that way you know the drain is coming from that circuit.

Thanks, that was what I was thinking I should do.

[E30 Fitment]

I'm not sure if your car will have the same problem--probably not--, but my car had the same issue of losing battery in one day, and the problem turned out to be a wrong relay (here's a link to a picture: https://i.ytimg.com/vi/yLJ9wtuwjBU/maxresdefault.jpg , if you look up e30 main relay you'll find it; it's the white one on the left). It turns out someone put an incorrect relay with the wrong pins and it meant that power was always being sent to it constantly (even when the car was off). You can check this by disconnecting and reconnecting the battery connection point at the front of the car, and if you hear a click at the fuse each time it's connected, then you know that's your issue. You can PM me if you want to know more about it.

[Andre3127]

I'm not sure if your car will have the same problem--probably not--, but my car had the same issue of losing battery in one day, and the problem turned out to be a wrong relay (here's a link to a picture: https://i.ytimg.com/vi/yLJ9wtuwjBU/maxresdefault.jpg , if you look up e30 main relay you'll find it; it's the white one on the left). It turns out someone put an incorrect relay with the wrong pins and it meant that power was always being sent to it constantly (even when the car was off). You can check this by disconnecting and reconnecting the battery connection point at the front of the car, and if you hear a click at the fuse each time it's connected, then you know that's your issue. You can PM me if you want to know more about it.

I hear a click in my car, but I don't know if it's that issue. Are there other places that click can come from?

[earthwormjim]

Put a multi meter in line to your negative battery terminal to check drain. Then pull each fuse until you see the drain drop, that way you know the drain is coming from that circuit.

I think it's easier to just pull the fuse, then plug the multi meter into the fuse terminal. Then you don't have to even unbolt any big battery terminals.

[pj29]

Put a multi meter in line to your negative battery terminal to check drain. Then pull each fuse until you see the drain drop, that way you know the drain is coming from that circuit.

So, I did this yesterday and I only saw a 20 mA draw on the battery when everything was off, but it still wasn't holding a charge for more than a day. With 20 mA, I didn't even check fuses for a drain, didn't seem worth it.

I thought the battery was good, it charges up and reads around 12 A after charging. it's only 3 years old, but maybe the battery is bad.

[noid]

Whats the voltage of your battery after driving it with the car off? What is it with the car on?

Have you load tested the battery at autozone or similar?

[PDXPeter]

Might also want to get the alternator checked.

I had a recent issue and found that the alt belt had jumped the pully and was sharing the center pully with the PS belt. It wasn't effectively spinning the alternator causing the batter to fail to charge. The issue became very apparent when my coolant line popped and soaked the bad belt.

[ELVA164]

20mA is normal. Battery and alternator are the main suspects.

[pj29]

20mA is normal. Battery and alternator are the main suspects.

Yup, it seems like the battery was the culprit. Got a new one and haven't had the same issues so far.

[ELVA164]

Glad to hear it!