|
|
crazi
New User
Sep 8, 2007, 3:36 PM
Post #1 of 4
(2253 views)
|
96 jimmy a/c control
|
Sign In
|
|
I have a 1996 gmc jimmy and my heater and a/c will not switch over totally from defrost to any of the dash vents when you switch the selector dial to them.I checked the vacuum from the engine to the vacuum reservoir and out to the heater/a/c control valve and all is fine.I have vacuum at the control valve/selector, but it does not switch when you turn knob. Is the vacuum control valve behind the a/c and heater controls bad?
|
|
| |
|
Tom Greenleaf
Ultimate Carjunky
/ Moderator
Sep 9, 2007, 3:12 AM
Post #2 of 4
(2245 views)
|
Re: 96 jimmy a/c control
|
Sign In
|
|
As you know - default is defrost mode. If vacuum makes it to control head is still has to be sent on to diverter doors. Anywhere it can't do that is the fault. I'd think you could hear it leak but if control head just can't route the request it might not make a noise, T
|
|
| |
|
crazi
New User
Sep 10, 2007, 9:36 AM
Post #3 of 4
(2241 views)
|
Re: 96 jimmy a/c control
|
Sign In
|
|
so I guess I will try replacing the vacuum control valve.Maybe the valve is not diverting the vacuum to the other selections on control knob.Could that be the problem?Thank you for your thoughts and help.
|
|
| |
|
Tom Greenleaf
Ultimate Carjunky
/ Moderator
Sep 11, 2007, 4:34 AM
Post #4 of 4
(2238 views)
|
Re: 96 jimmy a/c control
|
Sign In
|
|
The control head is a tough job to replace. It would be nice to get to the air box and check for vacuum making it to the doors and see if it makes it there. Some can be actuated by hand so you know which ones do what. Watch out for anything to do with air bags! I think most vehicles use a solid yellow wire so don't mess with them, T
|
|
| |
|