Railmaster.

Just buy a new battery if it's like five years old, even if it is not the battery causing the problems right now it will cause You problems within a Year or so and leave You stranded when You least expect it!

911chick

Picked up a new battery today. I'll start doing some initial diagnostics next week. I'm prepping for a three day motorcycle ride right now, so the car is next in line. Thanks for the input. I have an appointment to take it in on July 30th for the headlight **** issue, but I'd rather not pay someone else to do tedious hunting for the mystery battery draw.

wicks

Here's a consolidated list from this thread of things to check:

- Can the power windows be operated with ignition off out of car?
- Is glove box or frunk light sticking on?
- Door switches (int. lights) sticking?
- Are any relays hot?
- Test amps to check individual fuse box circuits for draw (see link below)
- Any hidden aftermarket accessories?
- Check engine lid light in the dark with lid closed
- Does your alarm circuit throw a (double flash) of the red door buttons when you lock the car indicating a closed circuit and a small batt. drain?
- Ten seconds after locking, red diodes will give "quick DOUBLE flashes" if there is an open circuit. (Items monitored by alarm are: doors, engine & trunk lid lights, glove compartment, rear stowage compartment doors (rear seats delete), radio, immobilizing circuit in ignition, interior lights.)
- Ash tray light?
- DME relay or other relay could be bad
- Fuse one is CCU, which can have bad diode - see Tore B notes

Draw measuring procedure: https://www.bergvillfx.com/porsche-9...-measurements/

911chick

You are awesome! Thank you so much. I'd been cutting and pasting a bunch of replies and was going to go through them one at a time. This is so much easier!

911chick

This procedure states it's for the 964 or 993. Is it also applicable to the 996? I'm assuming it is. Thanks!

ToreB

The linked procedure is meant for the 964 and 993 since it mentions the common culprits in these cars. These are not applicable for the 996, but the general methodology of finding current draw could be used in any car.
Cheers,
Tore

911chick

Great, thanks. I've done the parts I understand and will have to figure the rest out later. I've been doing some motorcycle modifications for an upcoming trip, so the Porsche has taken a backseat recently.

RE: this point from Wicks' list.... "Does your alarm circuit throw a (double flash) of the red door buttons when you lock the car indicating a closed circuit and a small batt. drain?" I am not seeing the "red door buttons" he's referring to. Is it something my 996 doesn't have? I do get the quick double flash on the dash light for the alarm, and two parking light flashes along with one horn beep, when locking the car.

mf_rsr

Fuse #4 (power window regulator - 30 AMP) is drawing a decent voltage even when the car is parked. When I remove it my voltmeter reading drops significantly.

Am I right in thinking the above is probably the cause (my power windows still work once the ignition is off).

If it is, can anyone point to the PET diagram number which contains the door jam switch Vandit references as a starting point for some investigation and new parts please :-)

fyi - rennlist now has so many adverts on it that it nearly breaks my laptop!

***new bit - is there a wiring diagram of the fuse 4 circuit - would it be worth checking what else is potentially on there?***

Rocket Rob

The door contact switch in on PET page 903-06 #28.

As for the ads on Rennlist, I don't see any. Have you tried using an ad blocker? I am using uBlock Origin.

mf_rsr

Cheers for that - I'll refer to the PET manual.

Once logged in to Rennlist most of the ads disappear thankfully!

***new bit - is there a wiring diagram of the fuse 4 circuit - would it be worth checking what else is potentially on there?***

Just found this and this which may help others:

https://rennlist.com/forums/964-foru...ferrerid=19642
http://forums.pelicanparts.com/porsc...ml#post6169470

becausephilchow

I'm getting a pretty crazy battery drain in my 964 Cabrio also. Battery would go dead within 24H, not sure what the problem is so far.

Will give that list a check that was posted above!

wicks

Hi all - I've tested the following and no result:

- Can the power windows be operated with ignition off out of car? NO
- Is glove box or frunk light sticking on? NO
- Door switches (int. lights) sticking? NO
- Are any relays hot? NO (I ASSUME THIS IS MEANT TO BE CHECKED WITH IGNITION OFF)
- Any hidden aftermarket accessories? NO
- Check engine lid light in the dark with lid closed NOT ON
- Does your alarm circuit throw a (double flash) of the red door buttons when you lock the car indicating a closed circuit and a small batt. drain? Ten seconds after locking, red diodes will give "quick DOUBLE flashes" if there is an open circuit. (Items monitored by alarm are: doors, engine & trunk lid lights, glove compartment, rear stowage compartment doors (rear seats delete), radio, immobilizing circuit in ignition, interior lights.) NO - THE DOOR LIGHTS BLINK 20 TIMES MORE QUICKLY WITH A SINGLE BLINK, THEN SLOWER SINGLE BLINKS
- Ash tray light? ONLY TURNS ON WHEN HEADLIGHTS SWITCH ON

- DME relay or other relay could be bad MY CAR HAS NO DME (1994 3.6turbo)
- Fuse one is CCU, which can have bad diode - see Tore B notes

Does this mean my CCU is bad?

ToreB

If your door lights blink fast when locking, there's a problem with one of the things you mention.
Use a Porsche compatible OBD diagnostic tool to log on to the alarm module and check the fault codes and events memory to find the culprit.
Cheers,
Tore

wicks

Oh - I read that the TWO FAST BLINKS or DOUBLE FLASHES was the sign of that, rather than my pattern of single blinks.

Anyone around LA have an OBD reader that can do this? I have a 90s OBD meter was used mostly to diagnose the old D90...

On a '94 3.6 turbo, is the alarm control unit under passenger seat (right side seat)?
.

wicks

If I buy this, can I run the 'scantool' freeware to test for these alarm-connected issues? https://www.bergvillfx.com/index.php...4-and-993.html