![]() |
|
![]() |
#1 |
Registered User
![]() Join Date: May 2013
Location: Coppell, Texas
Posts: 176
|
Heater Control
I've got a stock setup with AC and the temperature control never quite seems to completely shut off the heater valve. Similarly the AC system checks out, but never quite gets cold. It seems like the AC is fighting the heater.
I have already replaced the Heater valve and check to make sure it is getting vacuum to operate. My next step might be to change out the panel control to make sure it is passing on the full vacuum to the valve. I guess I could just put a manual ball-valve uder the hood to shut down the hot antifreeze to the heater core in the warmer months.
__________________
1971 GMC C15 Sierra Grande SWB 1972 Chevy C10 Custom Deluxe LWB 2018 GMC Yukon Denali |
![]() |
![]() |
![]() |
#2 |
Registered User
Join Date: Oct 2005
Location: Overland Park, Ks.
Posts: 5,217
|
Re: Heater Control
There is a housing under the dash with a flapper in it. It is notorious for the flapper coming loose. That might be the problem or part of it.
|
![]() |
![]() |
![]() |
#3 |
Senior Member
![]() Join Date: Dec 2013
Location: Gods country East,Tn
Posts: 8,545
|
Re: Heater Control
^^
![]()
__________________
![]() 1967 Factory short bed - Old school '71 - 350 / 4bolt / 487 heads / Edelbrock C3BX Muncie M-22 4 speed / Hurst Comp plus Factory 12 bolt posi 3.73 / 255-70-15 Smoothed firewall / Factory cowl induction Power disc brakes / power steering / 3.5-5" drop |
![]() |
![]() |
![]() |
#4 |
Registered User
![]() Join Date: May 2013
Location: Coppell, Texas
Posts: 176
|
Re: Heater Control
Thanks, I'll check the diagram.
__________________
1971 GMC C15 Sierra Grande SWB 1972 Chevy C10 Custom Deluxe LWB 2018 GMC Yukon Denali |
![]() |
![]() |
![]() |
#5 |
The Older Generation
![]() ![]() ![]() Join Date: Aug 2006
Location: Montezuma, Iowa
Posts: 25,515
|
Re: Heater Control
-
Also may have a mouse nest in it keeping the diverter door from working.... LockDoc
__________________
Leon Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles (My Dually Pickup Project Thread) http://67-72chevytrucks.com/vboard/s...d.php?t=829820 - |
![]() |
![]() |
![]() |
#6 |
Registered User
![]() Join Date: May 2013
Location: Coppell, Texas
Posts: 176
|
Re: Heater Control
Got it fixed.
Let me explain for some other future poor soul, who messed something up while trying to fix something simple. After changing out all the old air vent lines, I re-positioned the cable for floor/defrost diverter controls with too much bend. I straightened out the path so now the lever on the control slide panel had its full travel. Because it wasn't able get to its intended end, it kept the temperature control from fully extending so it wasn't fully closing the vacuum line to the heater control valve. In essence, it wouldn't let the valve shut off the flow of hot water through the core. So in a way, it was a control issue. Many thanks! Thundar
__________________
1971 GMC C15 Sierra Grande SWB 1972 Chevy C10 Custom Deluxe LWB 2018 GMC Yukon Denali |
![]() |
![]() |
![]() |
#7 | |
Registered User
![]() Join Date: Dec 2015
Location: Prescott Arizona
Posts: 621
|
Re: Heater Control
Quote:
I have a broken lever, and other issues to work on, project #89.
__________________
1968 Long Bed 2016 Honda Civic Coupe EX-T ticket magnet |
|
![]() |
![]() |
![]() |
Bookmarks |
|
|