Cooling fans not working 2000 996

[luthir2]

Hello,

My 2000 996 C2 Cabrio has been overheating. Trouble shooting led to the cooling fans not turning on as they should (Stage 1 or 2).

I have replaced the driver side fan and the thermostat, all relays and 2 fuses.

Current Status

Stage 1 fans turn on with air con.

Neither fan/stage works with engine running (settings 180 deg and 200(?) deg).

With Durametric:

Key on (engine not running) I can start/stopboth fans and both stages using durametric

Engine running I cannot start the fans using durametric.

I have a new engine temp sensor. Both the temp in cluster and in durametric are working fine with the original s havent switched it out.

Any idea's? all I can think is it could be the ecu(?)

I appreciate any help.

Thank You!

Rick