2002 draining battery at night

[John Doll]

My battery in my bird drains to zero about every 4 days if cables are hooked up. I installed battery disconnect to potentially slow it down until I could find the problem. I cannot find anything except interior lights in rear view mirror that stay on intermittently. Don’t know if that’s the culprit but help is needed. Anyone have similar issues let me know what to do.
Thanks
Black02

My battery in my bird drains to zero about every 4 days if cables are hooked up. I installed battery disconnect to potentially slow it down until I could find the problem. I cannot find anything except interior lights in rear view mirror that stay on intermittently. Don’t know if that’s the culprit but help is needed. Anyone have similar issues let me know what to do.
Thanks
Black02

The six disk CD player is most likely the problem, find the fuse near the glove box and pull it out. If it solves the problem, update the radio ?

 

[blackdeluxe]

I don't drive my tbird very often; it sits, sometimes for a month or two. This has been fine for years, but recently the battery went dead. I couldn't get the battery to take a charge when it is connected to the car, even at high charge rates. Any idea why that would be? It charges fine when disconnected. I figured that maybe there was something drawing down the battery when the car is off, but I measure 0.05 amps of current, which should make the battery go dead in 1.5 months, give or take. Any idea what is drawing this tiny current? The current dropped by half when I pulled one of the mondo relay fuses in the trunk (#2), so there is more than one current draw going on.

 

[Redbird 02]

Don't know if this has already been discussed...my battery on my 2002 retrobird is draining while in the garage...no lights remain on except the red blinking diode on the dash...doors trunk and hood are all closed...it doesn't make any sounds. Is there a switch somewhere that has notoriously been draining batteries or is this something new.

Pull your radio fuse and see if the battery holds. That was my problem on my 02.

 

[Big Bird]

Could be something else, even battery itself, but when i first got my 05 it would not last 2 days of sitting.

Turned out to be the defective REM - rear electronic module was causing intermittent but often huge draws that were taking battery down

It is located below collapsed convertible top

It was then replaced and been fine since .. although battery, brand new just before the problem, lasted only 3 years - Mechanic figured battery life was hurt by the previous excessive draw problem

Is there a specific diagnostic test for REM?

 

[bird-dom]

Is there a specific diagnostic test for REM?

There are diagnostic codes for certain failure modes, but from my experiences with my 2002, the kinds of failures as described in this thread are caused by transistors in the electronics modules (both rear and front). Most cars I've worked on use the electronics module/computer to switch a relay on and off, where the relay handles the higher power. For some reason Ford decided to switch many of the power circuits directly with transistors in the electronics modules. The problem is that transistors wear out over time, and start to leak more and more voltage. Depending on how many leak and to what degree, you'll start to get battery drain problems. In my experience, relays will fail in a more catastrophic manner, which is a good thing because the problem is easy to detect, and the relay modules are in sockets so they can be easily replaced.

I had my FEM rebuilt which replaced all the transistors, and that fixed illumination problems I was having. I need to have my REM rebuilt, too. The REM handles a handful of lighting switches, and I see various amounts of voltage sent to the lamps, even though the car is off.