My temp rises above 220 but the fan never turns on. Relay checks ok. If I turn on the a/c on normal fan starts. I looked at the schematics in my haynes manual and it shows the relay to the ac/ switch grounding the relay (turns on the fan). But my manual lacks any other fan circuitry regarding the puter, so I could not check it. Since the cockpit display shows correct temp I'm assuming that the sensor is working correctly.

Any advice, things to check from here....

Thanks