Duke

I've just put my car back together after changing the headgasket, waterpump, front seals, all the belts and rollers, ported&polished and worked head, shimmed wastegate etc.etc.

Everything works perfect expect that the car gets too hot!
I had the same problem before turning the car to pieces but I found a faulty fuse so I thought it should be OK now but it isn't.

The fans come on at low speed but never when the temperature rises they never come on at high speed.

I tried using another cooling fan relay from a friends 951 but the fans still didn't run in fast speed. However, the strange thing is that my relay didn't get the fans to run in high speed in his car.
So... my relay seems bad but how come his working relay didn't work in my car??

I tried another relay but the fans still don't come on as they should.
Could it be a bad the temp sensor? Or perhaps both the temp sensor and the relay?

Thanks
Gustaf

ahofam123

Try turning on the ac. If the ac is on, the fans should be on high regardless of temperature. Also look into the temp switch on the radiator on the driver's side. Check to see if this is operational by jumping the two wires. If it is not the relay, temp switch, the fuse, or the actual fans, the only other thing that it can be is a molested wiring harness.

led

I second the temp switch suggestion, my car even had an early model one...