I have the same issue the oil temp light flickers. I have changed the oil temp sensor did not fix it, I tested the fan and it works and I've changed a part of the wiring where I thought there was a short, at first it flickered but now nothing. Anybody know how long it should normally take for the fan to kick on? I'm starting to run out of ideas and want to wait to change the fan control unit until I know for sure that's the problem.

 

Remove the wire from the sensor, with ignition on, short the end of the wire onto the engine, the fan should start to run. If it does, and you have a known "good" sensor, the fan will kick in at the right temp, whatever the temp light is saying.