89 LXi compressor not running

[lgrouper03]

I have an 89 LXi that I bought recently. I have been fixing up some things and am now working on the A/C. The compressor is not running unless I jump out the clutch relay (mounted on the radiator support near the compressor). This led me to believe that the relay was bad. Replaced with another that I know is good (took off another car that works), but still no compressor. The A/C cooling fan engages like it is supposed to. I suspected the low pressure switch - but if I unplug that the A/C cooling fan stops. So I think the pressure switch is working.

The only problem with jumping out the relay is that the compressor runs all the time when the ignition is on. I have installed a toggle switch for temporary purposes, but I prefer to find the root cause.

Anybody have any ideas?

[HONDA_99]

do you have pressure in the system?

[lgrouper03]

Yes. I just put in a full charge and it cools fine - provided that I "hot wire" the compressor (described in my previous message).

[HONDA_99]

i'll look in my haynes repair manual tonight, i might find electrical diagram for AC system.

[HONDA_99]

there are not that many components in AC control system; clutch relay, blower relay, AC control switch, pressure switch and thermostat switch.

[lgrouper03]

Thank you for checking this out for me. Just now, after studying the wiring schematic, I had another thought. My suspicion has centered on the clutch relay, although I think the relay itself is OK. I think the wiring going to the relay may be hosed up somehow. Hear me out:

If my memory serves me correctly, I am getting power to the coil side of the clutch relay. But the clutch still does not engage. I am not getting power to either terminal on the load side of the relay. Looking at the schematic again, I see that 'terminal 4' on the load side of the relay is electrically connected (or supposed to be) to 'terminal 2' - which is on the coil side of the relay. Assuming that something has happened to the connection between 'terminal 4' and 'terminal 2', I guess I could simulate the correct wiring by jumping between terminals 2&4. Perhaps I'll try that tonight and see what happens. It seems a little wierd that something could have happened to the wiring, but it's the path I'm pursuing now. When I got the car, I noticed that the clutch looked as if it had shorted out and burned. The wires from the inside of the magnet were hanging out. Maybe this short circuit and ensuing spark show took out a wire connection (?). I'm just thinking out loud. I'll let you know if I find out anything interesting. Thanks...