Gary Lew

Hi I have a 1995 968 that i am experiencing a battery drain . I have a new battery in the car but only drive it about every 2-3 weeks for a day or 2. Several times i have found the battery to be dead and need recharging. Does anyone have experience in this.

Retro

This sounds stupid, but... check that the dome lights are going off. Or turn them off. The hatch switches are fragile and cranky.

chudson

This has been reported by others. Generally it is the cooling fans for the radiator activating when the car is at rest. Remove the fan control relay and see if the mysterious parasitic draw disappears. Don’t forget to put it back in when you drive the car. I hope this helps

Cliff

Yogii

With me it was the underhood light that never went off. I disconnected that bad boy never to be reconnected again.

As you can see, various people have had various switches fail. Finding which one it is can be bothersome.

-Yogii
AKA 968 Novice

dlearl476

How old is your battery? I replaced mine this year because the alarm would drain it after a couple of weeks. 4 year old battery. Finally this year it would charge fine but failed a load test.

chudson

He stated it was new. Doesn’t mean it doesn’t have an issue, but new none the less.

A parasitic draw test is beneficial only if the draw is present when the vehicle is being tested. As for an intermittent draw, it either has to be caught in the act or a DVOM with recording/logging capabilities has to be left on the car and that will only confirm that a draw did occur at some point. It still has to be found and those who have had the radiator fans activate erroneously have rarely caught them in the act. Rule this out by removing the relay as I suggested in my earlier post. I hope this helps

Cliff

Gary Lew

This was a new battery but it also was the second one that this happened to . First battery lasted 6 months and the second is only 3 months old

DSMblue

The first order of business is to determine what circuit is causing the drain, then troubleshoot the circuit in question. Are there any particular symptoms that you have experienced? when I had a parasitic drain, I was able to isolate it to the interior light circuit. Specific issue that was occurring in my situation was interior lights were always on. Finally determined after much looking that it was the passenger side hatch strut that was not breaking connection when the hatch was closed. As Cliff had also pointed out, fans can also be an issue, as can alarm system (if present).

RCD7

I drive a '95 968 cab that has a battery drain issue which I suspect may be related to the interior dome light or identical trunk compartment light. Both lights have a 3 position switch, Off, always On, and On that should automatically turn Off in about 20 seconds. Neither light will turn off when switch in in the "delay" position.
My question: What controls the 20 second turn off function of these lights?
The light fixture itself, the trunk or door jam switch, one of the Relays in the Underhood fuse box or something else?
Any help would be greatly appreciated!
RCD7

DSMblue

I believe it is one of the relays. There isn't anything in the door pin switches or the lights themselves that have delay functionality. If not a relay, it could be in the alarm module.

RCD7

Thank you for your response. The chart attached to the underside of the fuse/relay cover lists relay G17 as the "control unit light combination". Any thoughts how to check if this relay is the culprit, other than trying to locate a replacement relay?
Also, what or where is the "alarm module" located?
Thanks,
RCD7

jsheiry

I had a poorly fitting glove box door not turning the light off 100% of the time. Only caught it when I was sitting in the car at night looking at the glove box area at the correct angle and noticed the glow through a few cracks. Normally daylight when troubleshooting and never notice.it.

DSMblue

Tracing the wiring diagrams, alarm module is located under the passenger side carpet just under the glovebox iirc. Circuit also runs through the power window relay, which is G7. If you do a drain test, pull fuse 8 to see if that resolves the drain. If it does, your issue is somewhere in the interior light circuit.

RCD7

I really appreciate all of your input. It's becoming obvious that I need expert help in diagnosing & resolving my 968 electrical issues. I don't possess a wiring diagram for the 968 and it's unlikely that I would understand it if I did. But, if I could obtain the appropriate diagram for the "internal light circuit", "power window relay" and/or "alarm module", this would be useful to the professional I hope to find to resolve the problem.
Another electrical gremlin has risen it's head. My right taillight and my right (amber) parking light are both OUT. Both take an 1157 bulb, and I just replaced both. However, I have the same issue as before. The Brake light function for the taillight & the Turn signal function for the parking light both function, but the Taillight & Parking light do not. So the problem obviously is not with the bulbs.
Although the dome & trunk lights apparently are part of the "internal light circuit", is it possible that the taillight & parking light malfunction is related to the dome & trunk light issue, viz., not turning off after 20 second delay?
Thanks for you anticipated input
RCD7

931guru

I have uploaded the wiring diagrams for the 93 968 here:

https://drive.google.com/file/d/1R1k...ew?usp=sharing

I will leave them there for a week, until you can dowload them. They are not for the 95, but there would be almost no changes in the wiring.

Good luck.