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  • 4 months later...

Sorry to dig up an old thread, but I also had a parasitic drain on the battery, and traced it to the clock-room lights fuse in the engine compartment.

96 OBW 2.5 AT.

After pulling the fuse, the drain rate is down to about 50mA.

 

Any advice on where to go from here? I can drive the car without cabin lights, but it gets old pretty quick.

 

What would the cause of the drain be?

bad grounds?

short?

something else?

 

I have maplights in front which are connected to the dome light power wire. Also a light in the hatch area because it's a wagon.

 

Any help is greatly appreciated.

 

eag

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Sorry to dig up an old thread, but I also had a parasitic drain on the battery, and traced it to the clock-room lights fuse in the engine compartment.

96 OBW 2.5 AT.

After pulling the fuse, the drain rate is down to about 50mA.

 

Any advice on where to go from here? I can drive the car without cabin lights, but it gets old pretty quick.

 

What would the cause of the drain be?

bad grounds?

short?

something else?

 

I have maplights in front which are connected to the dome light power wire. Also a light in the hatch area because it's a wagon.

 

Any help is greatly appreciated.

 

eag

 

 

Put the fuse back in and start pulling bulbs. See what happens.

 

Are you the original owner of the car?

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No, I've had it since Feb '06, installed the maplight myself. Haven't had this sort of problem before.

 

The wiring diagram in the Haynes shows more lights than I have, I think newer outbacks had lights at the bottom of the door panels.

 

And what are step lights?

 

I'll start pulling bulbs and see what happens, thanks for the response.

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According to the circuit diagram I have, the fuse you pulled is for the 'always hot' circuit, powering not only 'room' lights and clock, but also the security/keyless-entry. If the excessive parasitic drain began after you installed the map lights, then of course look over your own work. If not, and there is no sign of problems with the room/luggage lights, consider the possibility that the radio (preset memory keep-alive and clock circuits) or security module might be the cause -- disconnecting each of them and rechecking current draw would be the ticket.

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No, I've had it since Feb '06, installed the maplight myself. Haven't had this sort of problem before.

 

The wiring diagram in the Haynes shows more lights than I have, I think newer outbacks had lights at the bottom of the door panels.

 

And what are step lights?

 

I'll start pulling bulbs and see what happens, thanks for the response.

 

Step lights are the lights at the bottom of the door panels.

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Step lights are the lights at the bottom of the door panels.

 

my 97 gt wagon has them, 97 obw limited does not.

 

is the clock/ room fuse also the radio, do you have an after market radio?

 

my 97 gt had a dead battery when i bought it since the bad HG caused it to not be driven. my guess is the alarm did it but i never figured it out.

Edited by johnceggleston
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I have an aftermarket stereo, one was installed when I bought the car as well. The keyless entry is an aftermarket alarm, which is on a separate circuit.

 

All the lights function properly, and the only connection for the maplights is a vampire clamp to the dome light power.

 

When the fuse is pulled, I only notice the interior lights not working, everything else seems to function fine. I pulled all the bulbs, one at a time, and I didn't notice any major changes.

 

What is the best way to check power drains from the lamps? Last night I pulled them when the positive cable was disconnected, and used a lamp to check current. Is there a way to do this without pulling the positive cable? I hate having to reset everything so often.

 

Thanks again.

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[...]What is the best way to check power drains from the lamps? Last night I pulled them when the positive cable was disconnected, and used a lamp to check current. Is there a way to do this without pulling the positive cable? I hate having to reset everything so often.

As long as the excessive parasitic drain stops when the interior lamp fuse is pulled, then a good approach is to put an ammeter in circuit by connecting it across the open fuse contacts. That way, you're measuring the current in that circuit alone.

 

Since your car has non-stock accessories and wiring, it could be harder to diagnose without being there. Visual inspection might be a key to finding the problem.

 

By the way, many trailer connectors have an 'always hot' circuit connection, and sometimes it gets corroded and conducts. If you have one, it's worth looking at.

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I get a reading of about 4 mA across the fuse terminals.

I bought a cheap harbor freight multimeter that reads up to 10A, and when I have the fuse in and check the gap from + post to cable, it's initially at up to 10A, then drops to about 60mA, because checking the gap causes the doors to unlock resulting in the high reading.

 

I found the drain at first by using the turn signal bulb from my motorcycle, and connecting the leads to the + post and cable. My guess is this caused the door lock circuit to stay open while it tried to unluck the doors, since not enough power was going through to actually unlock them?

 

So maybe I don't have a drain after all. I'll leave the fuse in and see if I notice any changes in battery performance, unless I should try something else first.

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