Thanks Athur that will help me. I am in the heating air conditioning business and can get strap on sensers for piping. I am going to get a stap on unit and install it on the space between the thermostat and the engin. Thinking 80 degree C for the on temp. This would bring the fan on high speed, or should I go 90 on and 80 off? Could you post a simple wiring diagram for this setup? I would like it to run only when the key is on. Please let me know what you think of that idea. A/C not working, not to concerned here in the great white north. By the way the wires on the air conditioner are loose and I was thinkig of bypassing it?