91 TC slow battery drain

[oldsguy]

There's about an 0.5-1 amp slow battery drain on this car. I've identified the source from the "lights" maxi fuse circuit in the main power distribution box but I don't know what else to check from here. I checked all the lights I could think of and couldn't find any, though I haven't locked myself in the trunk yet! Anyone have any suggestions as to what I should do next?

 

[Frogman]

Pull the trunk light bulb and see if the drain is still there. That was easy, huh...

There is quite a bit of difference between 500mA and 1000mA. Got to get a little more specific. But if it's the lights circuit... It's got to be a light that's drawing this power.

 

[oldsguy]

Rechecked. The amperage drain is 0.3a until the 60a lights fuse is pulled, then it drops to 0. Taking out the trunk light and unplugging the tail lights (a previous known short problem due to leaky seals) has no effect. Is this an acceptable range of drain? I am going to warranty swap my battery as it seems weak, then I will recheck to see if this drain kills the battery over time. The car does do a great deal of sitting during the summertime; never had a problem before but now it won't go for a day without requiring a jump.

Also, there are a few peculiar issues with the car, like turning off the dome lights results in the doors locking. Is this by design or is it an indicator of a wiring issue?

 

[Frogman]

If the total draw is around 300mA, then, I would think you are safe. you have to take into account accessories that are always hot, like the ecu... Which will draw about that.

 

[chris2523]

FWIW, i believe the draw in my mark VIII is around .15 amps.

 

[Gescojoe]

If you have the keypad on the door it's probably shorting out, check it.