ok, my A/C doesn't work and i have been trying to figure out the problem.

basically when i hit the A/C switch, nothing happens (magnetic clutch does not engage). the compressor does not turn on.

now i believe there can only be two things that are wrong here:
1) incorrect pressure in the system, either too low or too high
2) electrical problem causing magnetic clutch not too engage

so going through the FSM troubleshooting, this is what i have found so far:

- fuse is OK

- there IS continuity between the terminal-wire of the magnetic clutch connector and a ground

- all voltages at the A/C main relay connector are normal

- logicon switch inspected, and there is 0 volts at the BR terminal-wire, which the FSM says is the normal operation

- jumpered the wire between the pressure switch terminal-wires, turned the ignition to ON, and then turned blower and A/C ON. magnetic clutch still does not engage;
measured voltage across the terminal-wires of the pressure switch, and i get 12 volts


anyone have any ideas

edit:
oh, forgot to mentioned that it was 100 degrees F yesterday on the drive home from work. and i live in Canada, so that is freaking hot, lol

 

OK, the magnetic clutch is working as it should now, forgot to reconnect the compressor wire, DOH!

i jumpered the lines again, and it engages when i press the switch on the logicon.

can i assume then this is purely a pressure problem?
if so i'm going to take it to a A/C shop and get it pulled under vacuum to see if there are any leaks.

 

Yeh, could just need a recharge. Checking for leaks is mandatory at this point. Has it been converted to 134a? If not you should do that. Its really quite easy so don't let anyone tell you its a big deal. I have four brand new Sanden Compressors (original Mazda part) in the Mazda Box (part #FB04-61-450B) that I will sell for $275 each plus shipping. Most rebuilds more than that. Actually I have six of em but I'm saving two as I intend to drive 88's for a while. Oh yeh, these fit 86-88 S/4's. Now the parts places list the wrong dryer # down here. The good number for that at NAPA is 208657 or 33487. All this is just in case you have a need for them. I replaced my own compressor once with one of these and its been in there for two years. Gimme a MSG if you have any questions on this.

 

Yes, this is a low gas pressure problem. You need a recharge, but getting a pressure test first is a very good idea. Otherwise your new gas might just leak out the hole that let out the old gas.