I have a 99 honda accord thats in my signature but have some stock a/c questions. My a/c compressor clutch will only engage(rotate) on when I hook up a 12v source to it. So its not getting a signal from somewhere.
1) Relay(engine bay fuse box) should be good because I switched the relay around with another and same result
2) fuses are good

what else should i look for, havent hooked it up on the gauges yet, but it was blowin nice and cold 2 days ago then the next morning nothin because ac clutch isnt engaging.

 

if there isn't enough r134 the clutch will not engage. there is a pressure switch that tells the ECM it is okay to switch the compressor on when there is enough r134 in the system.

 

ok will throw on the gauges and report back.