And the battery drain saga continues: Alternator was not the problem. Put new one in anyway, mine had a dying rear bearing and was showing significant oscillation of the fan.

This little switch was, and is, the problem, drawing about .200 of my .243 draw. Even after I replaced it with new. The switch gets battery direct power from the over-the-engine harness, which is connected to the starter motor circuit straight back to the battery. When I connect this switch, a spark flies and an extra roughly .200 amps draw kicks in. The other switches nearby are also all brand new and don't create any draw.

Does anyone know about this switch and the harness? What does it do, how and why would it be "closing" and sucking current and passing it into the engine block with the ignition off? Some other reason this switch could be creating the draw? Everything is in very good shape - it would be hard to imagine the harness has failed. It is impossible to wire it backwards, the connectors are large/small, so you can't mix them up.

 

what is the part number? Where is it on the car? is this a turbo only thing?

 

Part number 93061711800. Maybe a 930 and 964 turbo thing. It is discussed (I think) in this thread - something to do with telling the cold start injector how long to fire...that could all be wrong and not about this switch on my M64.50 plant.

https://rennlist.com/forums/911-turb...-critical.html

 

Is the thermo-time switch supposed make a loud "click" sound a moment after shutting off the engine?

 

reading thru this 11 plus year old thread for first time. i've had the battery drain issues for a few years now. I purchased a ebay remote door lock module hoping to be able to lock / unlock the door without sticking in the key... it wouldn't arm the alarm which is fine. while working on it i screwed around with the passenger side door switch and lost the wire that goes into the front fender. I'm diggin into the wiring soon to see if i can find the battery drain source. i get 50 milliamps draw with the car off and alarm not armed... will try some of the many tricks the 964 braintrust has assembled.. did wicks ever find the problem and the 200 mA draw? and that goofy relay switching sound source?

 

You should get a magnet pen or some tape on a chopstick and get that door switch hooked back up.

Yes it was a short on the starter solenoid. Multiple methods but you can start with disconnecting various things and see when the current changes etc.

 

@wicks..
ah, bloody short on starter solenoid! amazing the journey you went through to find and fix! congrats and thanks for sharing your findings!

 

Hi, I had a parasitic drain on my 987, I hooked the multimeter to neg terminal and the other lead to the neg post of the battery....you'll need a helper or a set of alligator clips to do this. I started by having the hood lock latched with a screwdriver to simulate it being locked, I did the same with the driver door....make sure you remove the key from the ignition. I then removed one fuse at a time to see which would stop the drain if removed......I noticed with the PCM fuse removed the drain would drop down from 3.7 amps to approx 40 milliamps. So I bought a used PCM, but the current drain issue was not solved, but it did help me to narrow it down to sound system, I disconnected the amp and the drain remained, I finally removed the CD changer and the drain dropped down to 40 milliamps again....I looked at the pins in the back of the CD changer and there was evidence of rust.....I used an exacto knife to clean the pins the best I could....I then sprayed some PF Blaster in there and then rinsed it out with some alcohol.....it's been good ever since.