I'm trying to diagnose a problem which cropped up just yesterday. Car is a 1987 951.

Normally when you turn the key to the off position it kill power to things like the heat/airconditioning blower fan, headlight motor, etc. However, it appears that is no longer happening and even with the fan on "0" it still runs very slightly - enough to kill the battery overnight. I can actually hear it running even with the ignition turned off. (It's not the turbo pump I am hearing).

Before I take apart my steering column does anyone have any thoughts on what this particular gremlin could be? This problem cropped up yesterday after a short 20 minute ride. I wasn't working on the car or anything like that. Thanks.

 

You don't need to take the steering column apart to change the ignition switch just lay on ur back under the dash. It's a five minute change, two screws and a plug. I just did it!

 

I just crawled under the dash and see that it is pretty easy. I believe I was recalling the nightmare of a previous car where I had to replace the ignition switch which was on the column. Thanks for pointing this out.

Do you or anyone else have an opinion that this is what is causing the problem? Also, is the switch different than the key portion or the ignition switch? In other words, can I change the switch and still use the same key. Last time I did this on a Camaro I had to get a new key.

 

KlineS147 is right, is just two screws at the back, I just did it myself also but your problems sounds more like it is the tumbler than the electrical part

 

Any reason why you think it is the tumbler and not the switch from what I said? I looked in my workshop manual and see that they are two separate pieces. Hopefully it is just the switch. The last time I changed and ignition switch was over 20 years ago in a domestic car and the tumbler and switch were one piece.

Thanks!

 

Because I replaced the electrical part on mine last friday and I still have a problem similar to yours

 

Same thing with KEY OUT and not just to off? I believe some systems/circuits are still powered with the key in - at least they are on 996.. I can kill the battery on my 996 by leaving the key in. Not sure if thats the same thing for you.

 

OK, I understand. Before buying the replacement parts I am just going to disconnect the ignition switch and if everything goes off that should be the problem.

 

Yes, happens with the key out. It never behaved like this until yesterday. Since this is a street/track car it has a battery cutoff so now that it is charged again I just pulled the cutoff to stop the drain. However, I do need to get this resolved.

 

It is normal for the fans to run on low after shutting off the engine for a short time to cool down the radiator. Sometimes the "Thermofan Switch" in the radiator will stick in the open position and the fans continue on until the battery is dead. The "Thermofan Switch" is located under the top left radiator hose. It is cheaper than the electrical part of the Ignition Switch. Read post #10 in the 1st link below.

https://rennlist.com/forums/924-931-...r-fan-fun.html

http://www.clarks-garage.com/shop-manual/cool-05.htm

Cheers,
Larry

 

The problem with my car is the power to the entire car seems to be on now. You can flip up the headlights, turn up the fan, etc. - it's not the radiator fan, it's the heat/cooling fan.

I must be getting old but I am trying to get my body underneath the dash to get at those screws and I am about to kill myself. You take out the ignition switch from the back? Two screws? Five minutes? I need to lose 20 pounds and take yoga to get more flexible - I can't even see the switch!