More A/C problems
Thread Starter
Racer
Joined: Sep 2002
Posts: 337
Likes: 2
From: New Orleans La
More A/C problems
I have a 93 C4.
I've changed the low pressure switch and the system worked for a while
then quit.
Checked and clutch was not engaged.
I took it to a shop and they jumped the clutch and it worked great.
They said it probably was the electronic a/c control head.
Pressures looked good.
I changed the control head and it worked fine for a while then quit again.
Every time I disconnect the battery for a very short time it works fine again--for a while. Then quits!
Any ideas?
I've changed the low pressure switch and the system worked for a while
then quit.
Checked and clutch was not engaged.
I took it to a shop and they jumped the clutch and it worked great.
They said it probably was the electronic a/c control head.
Pressures looked good.
I changed the control head and it worked fine for a while then quit again.
Every time I disconnect the battery for a very short time it works fine again--for a while. Then quits!
Any ideas?
Safety Car
Joined: Apr 2011
Posts: 3,660
Likes: 22
I have a 93 C4.
I've changed the low pressure switch and the system worked for a while
then quit.
Checked and clutch was not engaged.
I took it to a shop and they jumped the clutch and it worked great.
They said it probably was the electronic a/c control head.
Pressures looked good.
I changed the control head and it worked fine for a while then quit again.
Every time I disconnect the battery for a very short time it works fine again--for a while. Then quits!
Any ideas?
I've changed the low pressure switch and the system worked for a while
then quit.
Checked and clutch was not engaged.
I took it to a shop and they jumped the clutch and it worked great.
They said it probably was the electronic a/c control head.
Pressures looked good.
I changed the control head and it worked fine for a while then quit again.
Every time I disconnect the battery for a very short time it works fine again--for a while. Then quits!
Any ideas?
The control head is part of a loop...it sends signals to the BCM (power module) to complete the ground in the clutch circuit. The wire to the clutch should be hot all the time, thus fooling techs that are unfamiliar with GM opt 68 A/C.
If the clutch is not coming on, but the blower works, the control head shows good displays, and the vents operate, get a BCM. Be ready...a real one cost well over $100
Pro
Joined: Aug 2009
Posts: 725
Likes: 4
From: Plano, TX
Clutches are controlled by the power module mounted in the evaporator core..on top.
The control head is part of a loop...it sends signals to the BCM (power module) to complete the ground in the clutch circuit. The wire to the clutch should be hot all the time, thus fooling techs that are unfamiliar with GM opt 68 A/C.
If the clutch is not coming on, but the blower works, the control head shows good displays, and the vents operate, get a BCM. Be ready...a real one cost well over $100
The control head is part of a loop...it sends signals to the BCM (power module) to complete the ground in the clutch circuit. The wire to the clutch should be hot all the time, thus fooling techs that are unfamiliar with GM opt 68 A/C.
If the clutch is not coming on, but the blower works, the control head shows good displays, and the vents operate, get a BCM. Be ready...a real one cost well over $100
How do I know all this? Because my 93 AC programmer has not provided an AC request signal since I bought the car. My control head and AC programmer are currently at Corvette Central being rebuilt.
Herb, have you tried pulling the codes on the control head. Do a search on C68 codes and you will find the way to do it.
Last edited by 93VettePilot; May 2, 2011 at 02:53 PM.
1984, 1993, ac, air, c4, chevrolet, condotioning, control, corvette, head, programmer, troubleshooting
