Endless RPMs

i got a 90 GTU and i just rebuilt the motor but whenever i turn the AC on on the Logicon, it doesn't turn on...i don't even hear the compressor turn on...is this a usual problem? can anyone give me some things to check? thank you

NZConvertible

Is the fan switched on? It must be or the A/C won’t run. Simple I know, but it’s caught me before...
It may have developed a leak and lost all its gas. It won’t run unless there’s gas pressure in the system. When you swapped your engine did you undo or disturb any of the A/C lines? A place that services automotive A/C can check this for you.
It could also be a problem with the Logicon. These suffer the “cold solder” problems common to these cars.

HAILERS

Your drier is in front of the radiator. It has two electrical plugs on it. Turn the key to on. Turn the a/c to on along with the fan. Jumper the two electrical leads together with a piece of wire. Did the compressor clutch pull in???????? If it did, suspect the system being low on freon or whatever is in there. Don't leave the compressor running for any length of time like this. This is jus one small step in finding out why it does not work. Might also go to the compressor, disconnect the single wire, and jumper it to the positive lead on the battery. Clutch should engage. Shows the clutch is good and checks to make sure the wire is connected to the compressor. My car had a bad relay up front there to the far left of the drier. Corroded.

Endless RPMs

NZ, im not too good with AC systems but im good with cars in general...but which fan are ou talking about? the fan that draws in air from the radiator? the mechanical fan that is...and HAILERS, am i going to need to drop the front end to check the drier? im horrible when it come to this...but i can make the ****** run like no tomorrow ...a lil more info is needed, possibly a diagram if possible...sorry, but like i said, im horrible with AC crap... :-\

NZConvertible

The interior fan must be running or the A/C won't operate. This prevents the evaporator coil (the bit that cools the incoming air) from icing up.

Endless RPMs

oh yea, the interior fan on the Logicon is turned on, but like i said "no go" ....i just need to know basically which wires to jump, what colors are they? (so i dont set fire or melt anything) then i will try some of these things...

RX7BEAR

the A/c pressure sensor is on the passenger side in the front of your car just under the support. were the overflow bottle is . Take the black plastic stuff out and you will be able to get to it . Then unplug both wires and jump them . your compressor will kick in then . The sensor is on the condensor on the pass side.