On my 86 951 the fan which cools the turbo seems to run extremely long. Say i'd drive it for 20 mins, then it runs for like, 20 to 30 mins. Sunday i drove it for maybe 45 mins, and the fan ran all day, cuasing my battery to become dead. when i hooked the jumper up to the car, it started to run again, after the car sat for a whole day without being run. what would cause something like this to happen?
thanks guys

 

what year/model you have? I can pull your wiring diagram and find out what sensor may be bad. A lot of times a temp sensor will fail, defaulting in making the fan run all the time. It would rather you be too cool running then too hot.

 

I vote Relay Relay Relay!

 

Had the same symptoms here. In my car the fix was to replace the temp sensor in the radiator. There is a decent troubleshooting guide at clarks garage (www.clarks-garage.net) that outlines how to determine what the faulty part is.

Also in the mean time, just pull the fan fuse whenever you get out to avoid having a dead battery later.

 

1986 porsche 951
thanks guys