The Ford Barn - View Single Post

Daves55Sedan · 10-18-2020, 05:52 PM

Ok so for the heater, I would say first check to see if the temperature control cable from the heater control cluster didn't fall off the clamp on the heater register housing under the dash. Possibly the bracket that holds the cable clamp broke off the heat register housing.
If that is okay and the end of the cable IS ENGAGED with the temperature control valve, you should be able to push the control knob to "High", which will allow water from the engine to enter the valve.
The water flows thru the valve only if you have the temp control knob pushed over to allow heat. You can throttle the knob down half way to decrease the amount of water the valve will allow to come in (thus reducing the amount of heat).
From the valve, the water comes out the outlet hose and into the heater core, then back out the heater core and returns to engine.
Make sure your heater hose connections are going to the right place. There should be an excellent illustration in your SHOP MANUAL.
While you are at it, check your right-air-heat-defrost cable to see if it is properly connected. Look under the dash behind the heat control cluster to see if the cable clamps are loose or disconnected.
Also check to make sure somebody does NOT have an inline heater hose bypass valve shutoff in the line going from engine to control valve. If it is shut off, turn it on. Some people will do this because the heater control valve has a rubber washer inside that stops the water when the heater control is off, but when it gets old, that rubber washer deteriorates and allows hot water in during summertime. The bypass valve reroutes the water back to the engine before the water can get to the heater core via the control valve.
So, in summary:
1) heater control cables inoperative by various means
2) heater hoses not routed to the proper locations.
3) aftermarket bypass valve shut off.

10-18-2020, 05:52 PM	#8
Daves55Sedan Senior Member Join Date: May 2010 Location: Granite City, Illinois Posts: 3,008	Re: Heater no hot air from Heater? Ok so for the heater, I would say first check to see if the temperature control cable from the heater control cluster didn't fall off the clamp on the heater register housing under the dash. Possibly the bracket that holds the cable clamp broke off the heat register housing. If that is okay and the end of the cable IS ENGAGED with the temperature control valve, you should be able to push the control knob to "High", which will allow water from the engine to enter the valve. The water flows thru the valve only if you have the temp control knob pushed over to allow heat. You can throttle the knob down half way to decrease the amount of water the valve will allow to come in (thus reducing the amount of heat). From the valve, the water comes out the outlet hose and into the heater core, then back out the heater core and returns to engine. Make sure your heater hose connections are going to the right place. There should be an excellent illustration in your SHOP MANUAL. While you are at it, check your right-air-heat-defrost cable to see if it is properly connected. Look under the dash behind the heat control cluster to see if the cable clamps are loose or disconnected. Also check to make sure somebody does NOT have an inline heater hose bypass valve shutoff in the line going from engine to control valve. If it is shut off, turn it on. Some people will do this because the heater control valve has a rubber washer inside that stops the water when the heater control is off, but when it gets old, that rubber washer deteriorates and allows hot water in during summertime. The bypass valve reroutes the water back to the engine before the water can get to the heater core via the control valve. So, in summary: 1) heater control cables inoperative by various means 2) heater hoses not routed to the proper locations. 3) aftermarket bypass valve shut off.