Okay, so I recently pulled and rebuilt my engine.

It's all in and appears to be running fine, EXCEPT, that it overheats and the cooling fan doesn't come on nor does the temp gauge show more than 3 bars.

What we know so far:

• Bled all air out of the system. The thermostat opens and hot water flows freely through the radiator.
• It's not a head gasket; nothing being pushed or bubbled through to the overflow tank.
• No coolant loss anywhere
• I tested the fan temp gauge (by shorting the harness plug (and the fans came on) so I assumed it was a bad fan temp gauge (the thing in the bottom of the radiator). I replaced it and the same thing (chance the new one is bad too, but unlikely. Particularly given the next info.
• Car starts at 1 bar on temp gauge. It goes to 3 and stays there no matter how long I let it idle/how hot I let it get.
• The ECT sensor is plugged in.

It is possible I damaged the ECT sensor while jacking the engine around to get it in and mated to trans (I had it all against the 'hump' at many points) . It does feel in tact though.

I'm thinking it's ECT sensor related. It's a bitch to get at that ECT sensor. Is there some way to trouble-shoot it through measuring inputs from wires on the ECM or ECT sensor plug (with a test light or a meter)?

Other ideas.

Oh, I did remove the AC and the heater circuit (track car). Is there something I need to do to fool the car since there's no AC and no fluid in the heater hoses?