a/c clutch stopped engaging. no power to green wire to clutch.

Q

QUIP'6'

Brian Roman
Joined
Nov 26, 2003
well the ac is charged and no leaks worked for years. now all of a sudden the clutch wont engage. i jumped the low pressure switch and the clutch still wont engage. checked the clutch wire and i have no power to green wire on the clutch. i ran a jumper to the green wire from alternator to the green wire and the clutch engaged. what could be the problem. thanks
 
That only happens to mine when the system has been empty of freon. Try disconnecting the positive battery cable for a few seconds and reconnecting it and trying the ac again. Also check for power to the ac relay on the passenger fender.
 
So if the relay has power something is keeping it from activating when you turn the ac on. I would still try disconnecting and reconnecting the battery positive cable. If that does not work it could be one of the other 2 pressure switches on the back of the compressor and on the line near the back of the compressor.
 
I don't have the wiring diagrams in front of me right now (have them at home) but I believe the green wire is energized when the ac relay on the passenger fender is activated. If that relay is not activating when you turn the ac on that is why the clutch does not engage. That relay is activated by the ecm when the ac is turned on. Your Powerlogger will show you if the ecm is requesting ac. Even if the ecm is requesting ac the relay may not be allowed to activate if any of the pressure switches are faulted. You should be able to remove the relay and jumper it there to activate the clutch. If you can do this it means that you have power at the relay but the relay is not activating. You can also check to see if there is voltage there to activate the relay when you turn the ac on. If that all checks out it could be the relay is bad which is an easy fix.
 
I'm having the same problem as the OP. Which relay on the passenger fender controls the A/C?
 
Black plug. Grey is the fuel pump
. I checked the relay and it has 12 volts but when I jump it the clutch still doesn't energize. By the way this is a friends car and doesn't have a scanner
 
I am not sure which one is the ac without looking. I think the other one is the factory fuel pump relay, if you pull it out the car should not start. There are only 2 relays and the map sensor in that area.
 
QUIP'6' said:
Black plug. Grey is the fuel pump
. I checked the relay and it has 12 volts but when I jump it the clutch still doesn't energize. By the way this is a friends car and doesn't have a scanner
Click to expand...
Then it sounds like it is one of the 2 pressure switches over on and near the compressor. I would still disconnect and reconnect the positive cable just for the hell of it. That has driven me crazy before until a friend of mine told me to do it and then everything worked fine.
 
Have you tried bypassing the ow pressure switch to see if the compressor kick on? That's 1 of the most common problems on A/C.
 
charlief1 said:
Have you tried bypassing the ow pressure switch to see if the compressor kick on? That's 1 of the most common problems on A/C.
Click to expand...

Yes I did with no change. When I UN plug it the idle changes or when I select air the car and idle reacts but no clutch and power to green clutch wire
 
Sounds like the green wire between the relay and compressor clutch is open.

RemoveBeforeFlight
 

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