common battery drains, let's have 'em...
 

I've got a battery drain on my 88 944S...I've unplugged the alarm relay....sound off common drains y'all have been frustrated with.

Thanks all!

(it's -4 here this morning...)

Accidentally hitting the turn signal when getting out of the car.

- Rear wiper motor seized but still trying to turn.
- Rear hatch lock seized but still trying to turn.
- Hood or trunk light still on after turning car off.
- Cooling fans continue to blow for too long after turning car off.
- Door pin stuck "closed" so stereo/lights continue to function after exiting car.

the most common source of battery drain is an aftermarket car stereo. the ones with removable face plates often have large drains when the face plate is in place. remove it and the drain goes way down. it's easy to see with an ammeter.

glove box lights also a common source

Mine was a faulty window switch. Changed it, no more drain.

2pm weather check

6C or 42F in Chatsworth, Ontario

Canadians buy a lot of real estate in AZ. 4 seasons and the Big Ditch in the north.

Door wiring pinched between the door and body.
Emergency brake handle electrical connection
Cigarette lighter connection.
If you replaced your stereo---you shorted a wire behind the box.
If you replaced your stereo--you pulled a hot wire off a connection and is now grounded.
Alternator diode short.

Transient Current Flow!

AGCO Automotive Repair Service - Baton Rouge, LA - Detailed Auto Topics - Transient Current Flow, A Silent Killer

Bad terminals and connectors.
AGCO Automotive Repair Service - Baton Rouge, LA - Detailed Auto Topics - Replacing Battery Terminals

Wire corrosion

Hood light shorting

Follow the Clarks garage info and pull each fuse until the drain on the battery stops.
Excessive Battery Discharge Rate

J_AZ

great thread!

Car alarm! Disconnected the connectors, no more drain. Same thing on my wife's little Corolla.

stuck relay

DME when door light switch is faulty and doesn't disengage

8pm weather check
80F in Palm Beach FL

Canadians also buy a lot of real estate in FL. 2 seasons (just the good ones) you can keep Autumn and Winter :)

Very timely thread...

I've kinda been neglecting the 944 for about a month, so hopped in it to take the kids to school yesterday--dead as a doornail. Sucked because I just replaced the battery just over a month ago.

Thanks for the education
 

Wow, I love to learn about stuff like this. I just purchased my first 944 as a winter project. The car runs and drives fine, just needs some TLC. Going through the electrical system and related components this winter, seems like a good idea. Lots of contact cleaner, multimeter and some time, will pay off with a dependable car next summer.

Weather Check - It's nice out in Michigan! Just wait a minute and the weather will change! Usually for the worse!

Honolulu weather check. 85 degrees and mostly sunny, just like every other day. Aloha y'all.

I found that I had a worn glovebox cover that allowed the glovebox light to come on randomly. The switch appeared to work fine but I think due to the switch plunger wearing into the cover it'd come on sometimes even when closed. I'd randomly find that the battery was drained. The trunk can cause this issue as well, as can broken interior lights. The interior lights can do weird things when they get brittle and fall apart inside.

Aftermarket alarms are notorious!

I feel lucky to not have the battery drain problem (yet). Car still starts on an old battery after being parked for the winter (oct - april).

Thanks for posting guys - I'm saving this info to my library.

Weather - unusually warm at 16 F, light snow falling.