**CRAZY** A/C issue
Thread Starter
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Joined: Oct 2012
Posts: 98
Likes: 0
From: Port St. Lucie Florida
**CRAZY** A/C issue
Hello all,
My car '97 coupe with 77k on the clock. Here are the codes I pulled:
P1571 Traction Control PWM Link
C1225 LF Excessive Wheel Speed Variation
B0432 Rear Defogger Relay Circuit
U1096 Loss of Communications with IPC
Shown in modules Radio, LDCM & RFCM)
As per usual RTD No Comm
I live in S. FLA and summer temps get pretty hot and humid. My wife likes to give the kids a treat by picking them up in the vette, every once in awhile. When she's in line and in idle, temps rise in the car to above 235 and A/C shuts off. I mean NO POWER, the a/c panel in cabin is dead, no blower, nothing. We let her cool off a little (vette not wife
) and its works normally again. I have searched the forum to no avail.
Thanks for looking and for any suggestions you may have.
Robert
My car '97 coupe with 77k on the clock. Here are the codes I pulled:
P1571 Traction Control PWM Link
C1225 LF Excessive Wheel Speed Variation
B0432 Rear Defogger Relay Circuit
U1096 Loss of Communications with IPC
Shown in modules Radio, LDCM & RFCM)
As per usual RTD No Comm
I live in S. FLA and summer temps get pretty hot and humid. My wife likes to give the kids a treat by picking them up in the vette, every once in awhile. When she's in line and in idle, temps rise in the car to above 235 and A/C shuts off. I mean NO POWER, the a/c panel in cabin is dead, no blower, nothing. We let her cool off a little (vette not wife
) and its works normally again. I have searched the forum to no avail.Thanks for looking and for any suggestions you may have.
Robert
Thread Starter
Advanced
Joined: Oct 2012
Posts: 98
Likes: 0
From: Port St. Lucie Florida
Cleared codes and took her out for a quick drive (vette not wife) and the following showed up:
P1571 Traction Control PWM Link
B0432 Rear Defogger Relay Circuit
RTD No Comm
But this time HVAC No Comm showed up. A/C was working fine, temps only got up to 210.
Thanks
P1571 Traction Control PWM Link
B0432 Rear Defogger Relay Circuit
RTD No Comm
But this time HVAC No Comm showed up. A/C was working fine, temps only got up to 210.
Thanks
Burning Brakes
Joined: Jul 2011
Posts: 1,097
Likes: 111
From: Fredericksburg Virginia
My buddies 97 had a dead HVAC and after further investigation found out that the ignition switch was the culprit. He could start the car and slightly wiggle, push the key and it would come on. He stopped driving it and is waiting to have me rebuild it for him. Maybe that is something else to look at. Bill Curly (sp?) might be able to help you out.
GL
Chris
GL
Chris
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Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
I was thinking the same thing but, when the ignition switch gets burnt, it usually effects more modules. The HVAC Head is plagued with poor solder joints. That another possibilty.
235 is NOT all that hot for a C5 In fact, its normal!!!
Here is post for you to look at:
- C5 ignition Switch repair - http://forums.corvetteforum.com/c5-t...ch-repair.html
Find the FUSE for the HVAC Head and when it stops working,,, measure the test points on top of the fuse to chassis ground. If it doesnt have FULL BATTERY at the test points, you need to repair your ignition switch. If the voltage is there, the wiring harness connector or the control head need to be inspected.
Bill
235 is NOT all that hot for a C5 In fact, its normal!!!
Here is post for you to look at:
- C5 ignition Switch repair - http://forums.corvetteforum.com/c5-t...ch-repair.html
Find the FUSE for the HVAC Head and when it stops working,,, measure the test points on top of the fuse to chassis ground. If it doesnt have FULL BATTERY at the test points, you need to repair your ignition switch. If the voltage is there, the wiring harness connector or the control head need to be inspected.
Bill
Instructor
Joined: Jul 2005
Posts: 103
Likes: 1
I have the same issue in my 97. I called Contemporary Corvette in Bristol PA and they knew all about this problem. The solder joints in the Control Unit itself break down after some years and causes the unit to cut off and on on it's own. They sell rebuilt units for about $150.00 or you could try and fix it on your own. I haven't replaced mine, but the Vett Shop I just took my car to [to replace the balancer] is also aware of this problem and he repairs them as well.
www.contemporarycorvette.com
www.contemporarycorvette.com
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Normally,, the loose resistors issue ONLY EFFECTS the vacuum florescent display and cause it to go dim or not light at all. The head still controls the AC system just fine
The only reason I mentioned the head unit as being defective and maybe related to solder joints is, ANYTHING is possible.
If it were me, I would just open up the head unit and do a quick circuit board inspection and see if there are any poor solder joints.
Bill
The only reason I mentioned the head unit as being defective and maybe related to solder joints is, ANYTHING is possible.
If it were me, I would just open up the head unit and do a quick circuit board inspection and see if there are any poor solder joints.
Bill
Instructor
Joined: May 2009
Posts: 129
Likes: 0
From: A.R.
I just recently went through A/C problems myself it started with my display being out.Then I checked my codes and had more than had ever seen.Blower would come on with car just sitting there I took apart the A/C head and checked and checked for bad solder joints.I seen Bill's write up about the ignition switch overhaul so I did that as well.and after putting everything back together and still having issues
I noticed when I would close my door my blower motor would turn on for a second, so after pulling the accordion tube and getting to the connections I straightened a few pins and everything came back normally.How long it will last I don't know but at least for now I'm back in the house in my chair and not out there in the heat.
I noticed when I would close my door my blower motor would turn on for a second, so after pulling the accordion tube and getting to the connections I straightened a few pins and everything came back normally.How long it will last I don't know but at least for now I'm back in the house in my chair and not out there in the heat.
Instructor
Joined: Jul 2005
Posts: 103
Likes: 1
Well I know it's been a few weeks since my last post but the bottom line on the HVAC control unit not working in my car, it was caused by the contacts in the ignition switch fouled and weak. Just as Bill Curlee's write-up said it could be.
Changed out the ignition switch and all is good.
Hope it works for someone else.
And thank you Bill.
Changed out the ignition switch and all is good.
Hope it works for someone else.
And thank you Bill.
