HVAC No Comm.
Thread Starter
Instructor
Joined: Aug 2009
Posts: 173
Likes: 5
HVAC No Comm.
Hello,
Ive read many threads on the vast amount of electrical gremlins the c5 can develop. I also tried to PM Bill Curlee to see if I could get some more info. without any luck.
The car was getting all kinds of crazy codes before the ignition switch was removed, cleaned, and reinstalled. That got rid of most codes. It did NOT get rid of the Hvac no comm though, and the intermittent fuel gauge working, not working issue. Also has a rear defrost code which I suspect is linked to the hvac no comm.
The HVAC panel was very dim before, and now nothing works on it. It doesnt light up at all or even give me a fan for heat or AC. The tubes in between doors were shook out like described in another thread too. Just looking for any ideas or input to get this car tuned and ready to go!
Also, this is a 98 c5. Thanks for any help.
Ive read many threads on the vast amount of electrical gremlins the c5 can develop. I also tried to PM Bill Curlee to see if I could get some more info. without any luck.
The car was getting all kinds of crazy codes before the ignition switch was removed, cleaned, and reinstalled. That got rid of most codes. It did NOT get rid of the Hvac no comm though, and the intermittent fuel gauge working, not working issue. Also has a rear defrost code which I suspect is linked to the hvac no comm.
The HVAC panel was very dim before, and now nothing works on it. It doesnt light up at all or even give me a fan for heat or AC. The tubes in between doors were shook out like described in another thread too. Just looking for any ideas or input to get this car tuned and ready to go!
Also, this is a 98 c5. Thanks for any help.
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
Sorry John,,, Was out of country for a while and have not checked my PMs... 
Examine the FUSE for the HVAC.. Measure the two test points (SLOTS) on top of the fuse to a good chassis ground with the ignition ON.
You should see full battery voltage on both test slots to ground. If it is LOW or no voltage, there is your issue.
I know that you stated that you repaired the ignition switch BUT,,, there could still be an issue with it. The voltage on the HVAC fuse should tell you tons of info.
Did you examine the ignition switch harness connector female pins to see if they were damaged or spread apart?
Post up what you find.
As for the fuel gage,, Check the chassis ground on the drivers side rear tire area. Make sure that the ground stud and eyelet are clean and tight.
Bill
Examine the FUSE for the HVAC.. Measure the two test points (SLOTS) on top of the fuse to a good chassis ground with the ignition ON.
You should see full battery voltage on both test slots to ground. If it is LOW or no voltage, there is your issue.
I know that you stated that you repaired the ignition switch BUT,,, there could still be an issue with it. The voltage on the HVAC fuse should tell you tons of info.
Did you examine the ignition switch harness connector female pins to see if they were damaged or spread apart?
Post up what you find.
As for the fuel gage,, Check the chassis ground on the drivers side rear tire area. Make sure that the ground stud and eyelet are clean and tight.
Bill
Thread Starter
Instructor
Joined: Aug 2009
Posts: 173
Likes: 5
Thank you for the info Bill!
I almost started wondering if you gave up on these c5's. Hahaha. Shame they have all the issues they have since they're still a great looking car and also a great platform for many different things....
We will check all that you listed and get back. This is getting frustrating, as I'm sure you understand.
I almost started wondering if you gave up on these c5's. Hahaha. Shame they have all the issues they have since they're still a great looking car and also a great platform for many different things....
We will check all that you listed and get back. This is getting frustrating, as I'm sure you understand.
Safety Car
Joined: Mar 2015
Posts: 3,638
Likes: 245
Hello,
Ive read many threads on the vast amount of electrical gremlins the c5 can develop. I also tried to PM Bill Curlee to see if I could get some more info. without any luck.
The car was getting all kinds of crazy codes before the ignition switch was removed, cleaned, and reinstalled. That got rid of most codes. It did NOT get rid of the Hvac no comm though, and the intermittent fuel gauge working, not working issue. Also has a rear defrost code which I suspect is linked to the hvac no comm.
The HVAC panel was very dim before, and now nothing works on it. It doesnt light up at all or even give me a fan for heat or AC. The tubes in between doors were shook out like described in another thread too. Just looking for any ideas or input to get this car tuned and ready to go!
Also, this is a 98 c5. Thanks for any help.
Ive read many threads on the vast amount of electrical gremlins the c5 can develop. I also tried to PM Bill Curlee to see if I could get some more info. without any luck.
The car was getting all kinds of crazy codes before the ignition switch was removed, cleaned, and reinstalled. That got rid of most codes. It did NOT get rid of the Hvac no comm though, and the intermittent fuel gauge working, not working issue. Also has a rear defrost code which I suspect is linked to the hvac no comm.
The HVAC panel was very dim before, and now nothing works on it. It doesnt light up at all or even give me a fan for heat or AC. The tubes in between doors were shook out like described in another thread too. Just looking for any ideas or input to get this car tuned and ready to go!
Also, this is a 98 c5. Thanks for any help.
