Ok, on my 90 camry, since I bought it ~1 month ago, I have had no A/C. I can turn the blower fan on and air blows fine, but when I press the ac button, nothing happens. no engine idle fluctuation, no relay click, nothing; apart from the green light in the ac button turning on. originally I suspected the mag. clutch relay to be bad so I poped open the hood and took out the relay... heres what I saw:
(eewww)
Becides the obvious fact that someone or something put grease in the terminal (I don't think it's dielectric grease, just normal grease), one of the terminals wasn't there (the lower right one). I tested for voltage @ the terminals according to what alldata said should be there, and no combination of connections resulted in any voltage. I also tried jumpering the connections to emulate the relay and nothing happened.
I tested the relay and it was fine, although it said "dimmer relay" on the side.
That, too, had my scratching my head. I unbolted the fuse/relay box to see if the missing connector was pushed down and out of its place, but there wasn't enough room to see anything, let alone reconnect anything. I tested the other 2 ac system relays and they both checked out.
here's some pics. I'm not sure if they'll help at all.
I'm lost on this one.