Heater Control

[NORTH]

My 65 was originally a ac car but now has no ac. The heat control on the dash does not work. I either have heat all the time, or if I disconnect the water control valve (which is new) I get no heat at all. I have looked up the vacuum diagrams and played around with the connections, but always get all heat or no heat. Has anyone had experience with a former ac car? Does the ac need to be operative for the heat control to work?

[Joe Vandatta]

Test to see if you are getting vaccum to the water control valve when you operate the heat control on the dash--could be in the line to the dash control or defective dash control unit.
Joe

[tbird5866]

The water control valve (on the RH spring tower) needs vacuum to it to open and allow water flow (and heat). No vacuum - no heat.The temperature control lever on the console regulates the vacuum to the water valve. You should be able to supply vacuum to the console temperature control with the AC/heat lever on heat or defrost position and send controlled vacuum to the water valve. Usually the temperature regulator in the blower motor housing is bad. It can be by-passed. Questions? tbird5866@aol.com

[Joe Vandatta]

Fordman,
I think I have a bad temp. control valve on my 66 with air cond. You say you can bypass it, how do you do this and what will be the result. I have either high heat or no heat.
Joe

[Joe Vandatta]

As the Fordman says, you should be getting controled vaccum to the water valve. I had the same problem (all heat or no heat) so checked the vaccum to the water valve to see if it was controled by moving the temp. control on the consoul and it was doing it's job okay--increasing vaccum as you move it to warmer so the water valve is at fault. Since you have replaced the water valve it must be the temp. control valve in the blower housing or in the vaccum lines someplace I think.
Joe

[tbird5866]

If you will run a vacuum hose from the brown nipple on the control valve to the water valve under the hood, you will have bypassed the bad temperature regulator. When you move the temp lever to MIN you will reduce the vacuum to the water valve and restrict the flow of water. With the lever at the MAX position, you will supply full vacuum to the water valve and have full water flow. Of course, all this assumes the water valve and the temperature regulator are working properly!