Chuck Z

Hello all, long time....

The AC in my 968 hasn't blown cold air since I bought the car so, as a first step, I decided I would add freon today and the AC now blows cold. Guess we'll see if it holds pressure. It's still an R12 system btw. When I took it for a test drive, the engine temp went higher than it has ever gone. Went up to the last white mark on the gauge. Usually runs just above the lower white mark and never fluctuated much at all. Didn't overheat and would come back down if I lowered the AC output.

I lifted the hood when I got home and only one cooling fan was running. Obvious diagnosis would be the in-op fan or, something related to that fan is bad?

Was thinking I could switch the electrical connections from one fan to the other and see if the in-op fan starts up?

Thoughts?

TIA for any input/advice.

Paul Waterloo

It shouldn't be that hard to troubleshoot, the fan on my 951 works very wonky with the AC on, just turns on/off/on/off. I spent a lot of time troubleshooting it and replaced the resistors, but still haven't got it figured out.

There are relays, fan resistors near the windshield wipers, temperature sensors and I'm sure some input from the AC system to ensure the fans stay running with it on.

I am building a house in FL right now, but hopefully I will be back in Chicago for the summer in about a month. Would love to come by and see the car and help you troubleshoot it if you don't get to it first. I see that it was on ebay.

Chuck Z

Thanks Paul. Since one of the fans works, I'm assuming the problem is with the in-op fan. Other than the fan not working, the other seems to run and work as it should... Maybe switch connections and see if the in-op fan work or confirm it's dead.

Daditude

I would take a look at Clark's garage- he has an excellent troubleshooting article re: 944 fans. I had the same issue it was the resistor block.

here is a link:

http://www.clarks-garage.com/shop-manual/cool-01.htm

- Daditude

Paul Waterloo

I do have a set of good fan resistors if you need them.

Chuck Z

Thanks Paul. Sent you a PM.

Paul Waterloo

Chuck, was looking at the wiring diagrams yesterday and doing a little research. Found a great thread on the relay, will have to check that for my 951 as it still has the fans that come on for about 5 seconds, go off for 5 seconds, on/off. Here is that thread:

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

And here is the 92 wiring diagram with a couple of mark ups. I'll be in the garage tomorrow if you want to stop by, could spend some time looking at it with you.