zenithblue993

After months of trying to figure out where my battery drain is coming from I have run out of ideas. Ill charge the battery up to 100%. Drive around atleast once a day and 3 -4 days later the voltage will be around 12.4 volts when i check it in the morning.

The alternator is a replacement one I got a 1.5 years ago, never had issues until the last couple months..

The battery is brand new interstate battery, about a month old. Just to rule out the battery as the problem, I took it out of the car charged it to 100%. Checked the voltage 4 hours later and it was 12.78 volts. The next day 12.77 volts. The next day 12.76 volts. So I think my battery is good.

What I have tried:
- Pulled all the fuses one by one, nothing drawing current. Using the test with the multimeter, the car is drawing around 30 millamps. So that's good.
- The CCU fan does turn off after about 10 -15 minutes.
- I have replaced the voltage regulator twice in the alternator. When I drive my little voltage cigarette lighter reads 13.9 - 14.2 volts depending on the headlights, or AC is on.

At this point, I was considering rebuilding my alternator but If i get a solid voltage is there any point? Any ideas?

k722070

when you close the door and set the alarm/lock does the led in the door flash in the correct sequence?

how did you test? with the multimeter in parallel to the ground?

JasonAndreas

Are you putting the multimeter inline BEFORE pulling the ground wire connector from the battery? If you just disconnect the battery and then put the multimeter between the connector and the minus post, you will miss any relays that are stuck and drawing current.

- Switch the ignition on and off, remove the key and close the door.

- Install multimeter between battery minus pole and vehicle body. Then disconnect the vehicle ground strap at the body mounting point. This will prevent interrupting the circuit and allowing the relay to collapse.

Endoman

Mine was traced to a faulty door switch.

pp000830

What is the voltage at the battery when the engine is running? Should be at least 13.5 volts and can be as high as 14 Volts or so. This is a definitive test of your alternator,
Other than your frunk, glove box, engine lid or turn signal light being left on due to a switch issue a commonly missed item is when an aftermarket audio amp is wired improperly so it remains powered when the ignition is off.
Any resting voltage of 12 volts or more will start your car except in very cold weather.

Hope this helps,
Andy

Andy

Vandit

+1 to what JasonA said. The key to using the multimeter for finding a drain is to not break the circuit.

My method is to loosen the negative terminal, but don't disconnect, then place one MM prong on the terminal and the other on battery post. Carefully disconnect the terminal while maintaining your MM contacts, effectively keeping the circuit closed.

It's important to have something holding the hood light switch closed while you do this, otherwise you typically blow the fuse on the MM.

zenithblue993

Update: So I was connecting the multimeter wrong, removing the ground cable and then connecting it was the issue. After correcting the problem I had draw on the battery!

Total of about 390 milliamps which is not good. After pulling fuses I have identified two issues:
Fuse 1: "Blower inside compartment"
Pulled this fuse dropped down to 60 milliamps. So it was using over 300 milliamps!

Fuse 12: "diagnosis, clock, emergency flasher, rear windshield wiper, on-board computer"
Pulled this fuse and dropped down to 29 milliamps, so this fuse was using an excess of about 30 milliamps

Also my led in the door i think is normal, it flashes rapidly when i lock the car, then eventually flashes once every 2 or 3 seconds.

I will do my research on the fuses by any leads?

ToreB

Normal current draw ia 15-30mA in a 964/993.
Fuse 1 is the CCU with fan, a normal current draw in active mode. You state it is shutting down normally, is it turning on when you insert the fuse? (at ignition off) It shall only power up when turning on the ignition, and turn off almost immediately if the ignition has been on only a few seconds.
Fuse 12 is Terminal 30, lots of things are connected to this. I would guess start with the door lock/alarm module circuits. Check both door contacts. The most probably cause for such issues are the door switches. However, just turning off the lights will not stop the drain, a failing door switch will keep circuitry (and a relay) active at ignition off. A quick test is to try the electric windows, if they work, you have a failing door switch.
The best way to check this is to measure the current draw from the battery at ignition off, with doors and engine compartment closed, and with the luggage compartment lock depressed and locked.
Cheers,
Tore

zenithblue993

Thanks tore for your input. I went out to the garage and did some more testing.

I drove the car around, parked, locked the doors, pushed the hood clamp and took a reading on the current.

Again it said around 387 milliamps. I waited this time before I pulled fuses. After about 20 minutes, pretty much exactly 20 minutes, it dropped to 60 milliamps without me touching the fuses. So i assume my CCU is turning off and there's no issues there...

I also checked the widow switches, and they only work when the ignition is on. If I turn the car off, they don't work even with the key still in the car. So I guess it's not the door switches

Now I drew my attention to fuse 12. With it in, there is 60 milliamps on the multimeter. I pulled it, the milliamps dropped down too 23-25 milliamps. Then I put it back in, and 33-35 milliamps were being displayed, pull it out again back down to 23-25 milliamps.

I wonder whats going on here.

nsully

I had a similar issue with battery drain about a year ago. Did the same multimeter process you are, and found #38 to be the culprit. Fuse #38 is for the radio. I pulled it and haven't had a problem since but I also haven't had a radio. It is the original radio with the removable face plate - internal malfunction. Can't decide whether to repair it or upgrade.
Good luck with the hunt,
Neil

ToreB

Do you have a tachometer with the on-board computer? The LCD backlight circuit in this is known to fail, and this can prevent the backlight from turning off when you lock the car.
Cheers,
Tore

zenithblue993

Hmm I do have a tachometer in my tip, I looked and when lock the car the displays goes off. I will do further testing this weekend. thanks!

zenithblue993

So appearantly it wasn't dark enough when I checked the tachometer display the first time. I looked again tonight and It remained on when the car was off and locked! I see the blacklight still lit.

You were correct!

Do you know If its just a solder joint on the tach or something? I didn't find much info on the search. Thanks

zenithblue993

Just saw you page on the matter!

http://www.bergvillfx.com/obcrepair.html

Pr William

Is it normal for the CCU fan to continue on even after the ignition is turned off? Is it supposed to run for 10 to 15 minutes after the car is turned off?