Need some more cooling help

I changed the heater core in the 89 four cylinder today, and the heater works fine. A new best time, as I posted in 5.0 tech, 5 hours and 33 mins!

I drove it the other night, and while idling, the temp gage finally went up about 3/4 of the way to the top, ie, the 240-250 range, and the cooling fan never came on.

I checked it today, and the fan works when 12 volts is applied.

With the ac on, (no belt) and the pressure switch jumpered, there appears to be 12 volts at the fan connector, but the fan won't run.

Any suggestions? Where is the fan relay. I am more concerned about the engine cooling than the ac right now.

Also, where is the coolant temp switch for the fan, the one for the gage, and the ECT for the computer? Are they two or three different senders?

Thanks.

2.3lxhatch, thanks. I turned the ac on, w/o a belt, and jumped the pressure switch, and got 12 volts at the fan connector, but the fan won't run. It runs fine if jumped to the battery.