Regulatori

I recently purchased a 93 C2 and it's been perfect for the past week. In the past few days though I'll go out in the morning and it won't start. Everything turns on but it won't crank. I've been messing around with a lot of the features on the car in the past few days so I'm thinking that I have accidentally left something on and not know about it....but I've gone over everything and find anything.

Also, is it normal for some of the electrical stuff to work without a key in the ignition? For example, my key can be out of the ignition but my windows can still be automatically rolled up/down.

There has to be some electrical draw coming from something....I just can't figure out what. It's a brand new battery too.

Indycam

Does the alt light come on when you turn the key to the on position ?

Regulatori

I'm at a friend's house right now....I tried to start the car, it didn't start, and I took my other car. I didn't spend a lot of time going over it. If I remember correctly, the alt light did come on but I'm not 100%.

Indycam

Check when you can and then post if it does or does not .

Regulatori

Nevermind, just found a good tech section in Adrian's book that should cover this issue.

Henry964

I also have a 1993 C2, I had to change a lot of batteries, I am on the third new one after 3 years ownership and so I decided to put a cut off switch on the last one, it was the end of my dead battery problems, most 964 owners here have done the same since our cars are week end/track toys and not Daily drivers

Regulatori

At first we thought it was the battery because the previous owner rarely drove the car and it sat on a truck being shipped for 14 days.

But with the key out of the ignition we started checking fuses to see if there is any draw. We found that almost 50% of the fuses were still hot even with no key in the ignition.
Hot fuses
1-LH/RH Blower fans
2-Oil Cooler blower
3-Horn
4-Power windows
6-R Power seat
7-Cigarette lighter
8-L Power seat
11-interior lights/clock
12-Central locking
13-Sunroof
14-Foglights/reverse
16-ABS
35-DME
37-Rear spoiler
38-Radio

Seems odd that all of those are hot with the key out of the ignition. Maybe something faulty with the ignition.

Indycam

What does Adrian's book have to say about that ?

LouZ

When you check for Hot fuses, remember that when you turn off the ignition and remove the key, a number of circuits remain hot until you open the door (such as windows, sunroof, etc), or until a timer shuts off the relay.

Regulatori

It just took an odd twist.

We pulled all of the hot fuses individually to see if there was a change in voltage and nothing.

But here an odd thing.

3-4 days ago I switched out the existing aftermarket chip (FVD) with the original OEM chip....the FVD chip was a 93 octane chip and we only have 92 here. With the factory Porsche back chip in, everything turned on but the car refused to start. Before putting the old (FVD) chip in, I tried switching out the DME relay for a new one since I had one in my glove box..just figured might as well since it was handy and had nothing to lose. Still nothing. I then put the old FVD chip back in again and the car started up just fine....which meant the original Porsche chip was toast. I left the new DME relay in though and put the old in my glove box.

Well just now we decided to throw the original DME relay in. Now all of a sudden the fuses 35 (DME), 37 (Rear spoiler), and 38 (radio) are no longer hot.

Could a bad DME relay (the thing was brand new) make 3 fuses hot and enough to drain the battery?

DaveCarrera4

My old and new battery were both running down intermittently. I noticed that the little circulating fan on the dash HVAC control would sometimes be whirring after taking the key out of the ignition. Most sources say this is okay, but I think it continued to run and drain the battery after some days. If I hear it, I reach up under the dash and put my finger on the impeller to stop the fan. Battery doesn't run down...hmmmm.
DC4