73 Heater Control Valve...where is it??
Thread Starter
Intermediate
Joined: Jul 2011
Posts: 33
Likes: 0
From: Glen Ellyn IL
73 Heater Control Valve...where is it??
Hey everyone, so I replaced the heater core on the 73 (BTW, on MY car without AC I did NOT need to go through the dash to replace it...easy from engine compartment) and getting ready to hook it back up but can't find the Heater Control Valve or the vacuum hose to the valve. A couple years ago the heater core failed and it was bypassed. Chatted with mechanic that bypassed it and said he never would have removed the part or the hose to it in order to bypass...so??? where is it?? The car is pieces in my garage waiting for carpet so before I install carpet I want to make sure the new heater core isn't leaking. Can't drive to mechanic so need to do myself.
Any help on the location of where this part should be, and where the vacuum hose should be?
Thanks
Ted
Any help on the location of where this part should be, and where the vacuum hose should be?
Thanks
Ted
Le Mans Master
Joined: Dec 2007
Posts: 6,422
Likes: 591
From: McHenry Illinois
There is no control valve to control water flow to the heater core. Some AC cars have a water shut off valve controlled by vacuum. Your temperature control operates a blend door via wire cable to guide more or less air through the heater core depending on the temp you want.
Le Mans Master
Joined: Aug 2006
Posts: 7,413
Likes: 1,552
From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
Yes! That hot water shut off valve is just what you need.
Some of those valves OPEN with vacuum and some close when vacuum is applied.
See how yours works and tap into the appropriate vacuum line.
Some have it mounted on the passenger side not far from the firewall.
Once mounted you can splice in the heater hoses.
Some of those valves OPEN with vacuum and some close when vacuum is applied.
See how yours works and tap into the appropriate vacuum line.
Some have it mounted on the passenger side not far from the firewall.
Once mounted you can splice in the heater hoses.
Burning Brakes
Joined: Sep 2005
Posts: 1,050
Likes: 205
From: Lewes Delaware
Some people (I have) install manually operated valves (get them at Lowes, Home Depot, etc.) to shut off the hot water during the "non heater season"
Fran
Le Mans Master
Joined: Jan 2001
Posts: 6,672
Likes: 1,363
here is a cool isolation/recirc vacuum operated valve...
I was considering installing one of these on my car because it has Vortec heads..... so I saved the link. In case you want to maintain recirc with the heater isolated.
http://www.ebay.com/itm/HEATER-CONTROL-VALVE-Ford-GM-Hummer-Mazda-Pickup-NEW-/200464464182?item=200464464182&vxp=mtr
http://www.ebay.com/itm/HEATER-CONTROL-VALVE-Ford-GM-Hummer-Mazda-Pickup-NEW-/200464464182?item=200464464182&vxp=mtr
Last edited by carriljc; Jul 2, 2016 at 12:27 PM.
