AC Clutch won't engage
#1
03-11-2020, 05:25 PM
AC Clutch won't engage
I have an 02 CC with compresssor that was replaced a couple of years ago.
Here's my problem:
Just this morning I have no AC. Found out the clutch was not engaging.. Here is what I have done and think of what I should do next.
Checked all fuses and relays: all good.
Jumpered the low pressure switch. AC Clutch still no go.
Applied voltage directly to clutch connector on the clutch side and grounded the other wire. Clutch DOES engage.
Checked voltage on the clutch connector. None. (Suspect bad connector. Looks corroded)
Think I should replace the connector due to corrosion and age. I previously lost a Blower speed due to the same issue and replaced the connector with a heavy duty one and have had no new problems since.
Then moving up the food chain, I would then replace the AC Control Module in the dash. Problem with that is, no one makes new ones and the used ones may not work due to possibly two issues. 1. They show having a rear defrost switch where mine has Heated Mirrors, and 2. the old transfer case fluid in the vacuum hose issue. Mine had that and I had to change it once already for that problem. Don't want to do that again.
So is the module with the Rear Defroster module the same as the one for Heated Mirrors with just a different name on the front??
Lastly replacing the PCM. That was done about 4-5 years ago with a brand new one. Could it be bad??
TIA
Bill
Here's my problem:
Just this morning I have no AC. Found out the clutch was not engaging.. Here is what I have done and think of what I should do next.
Checked all fuses and relays: all good.
Jumpered the low pressure switch. AC Clutch still no go.
Applied voltage directly to clutch connector on the clutch side and grounded the other wire. Clutch DOES engage.
Checked voltage on the clutch connector. None. (Suspect bad connector. Looks corroded)
Think I should replace the connector due to corrosion and age. I previously lost a Blower speed due to the same issue and replaced the connector with a heavy duty one and have had no new problems since.
Then moving up the food chain, I would then replace the AC Control Module in the dash. Problem with that is, no one makes new ones and the used ones may not work due to possibly two issues. 1. They show having a rear defrost switch where mine has Heated Mirrors, and 2. the old transfer case fluid in the vacuum hose issue. Mine had that and I had to change it once already for that problem. Don't want to do that again.
So is the module with the Rear Defroster module the same as the one for Heated Mirrors with just a different name on the front??
Lastly replacing the PCM. That was done about 4-5 years ago with a brand new one. Could it be bad??
TIA
Bill
#2
03-12-2020, 12:59 PM
I replaced the connector from the wiring harness to the AC Clutch. No help. Still no voltage.
Rechecked fuses and relays. No help. Jumpered low pressure switch. No help.
So it is on to replacing the AC Control Module in the dash.
Any suggestions would be helpful.
TIA
Bill
Rechecked fuses and relays. No help. Jumpered low pressure switch. No help.
So it is on to replacing the AC Control Module in the dash.
Any suggestions would be helpful.
TIA
Bill
#3
03-12-2020, 02:53 PM
Work your way backwards from the clutch.
Do you have power at the hot side of the HVAC relay contact?
Do you have power at the hot side of the coil for the HVAC relay?
If you ground the other side of the HVAC relay coil does the compressor energize?
Are you getting a request for AC at the input of the high pressure switch on the back of the compressor? Do you see that signal at the output of the high pressure switch?
George
Do you have power at the hot side of the HVAC relay contact?
Do you have power at the hot side of the coil for the HVAC relay?
If you ground the other side of the HVAC relay coil does the compressor energize?
Are you getting a request for AC at the input of the high pressure switch on the back of the compressor? Do you see that signal at the output of the high pressure switch?
George
#6
03-12-2020, 07:30 PM
Manual AC.
I had to replace the Control Module before due to a bad transfer case switch. It sucked fluid into the vacuum lines and destroyed my original control module, so this one is number two since I bought the truck brand new in 2002.
I had to replace the Control Module before due to a bad transfer case switch. It sucked fluid into the vacuum lines and destroyed my original control module, so this one is number two since I bought the truck brand new in 2002.
