Vintage air - no heat?

[Rian_Colorado]

One of the last few things before I send the car to paint/body was to get the AC charged to make sure that I have no leaks, and that all of my wiring is correct. I followed the excellent write up from Paul B. and watched several videos, and after a couple of hours, bam. I have AC. went easier that I expected as the compressor kicked right over and all gauges read what they are supposed to, and held pressure for several hours. Think I'm happily leak free and will be blowing cold air (not that it's needed at this time of the year in Colorado!)

Kicked the AC off, and turned the dial over to heat, expecting to find it working, and.... NOPE. I had the motor running for a good 20-30 minutes, and the fan kicking on, so I know that the temps were up to needed...

I double checked my plumbing (input and output to the Coyote / heater control valve are as shown in the manuals)

The right site / Output of the heater control valve to the heater/evaporator is described as follows in the manual "From the right side of the heater control valve run and cut to length 5/8” heater hose from the valve to the footbox fittings. The hoses can go on either fitting.."
I'm assuming that is correct, and it makes sense as it would only be cycling hot fluid in a loop so......

I checked the hoses at the control valve, and the input hoses are both nice and hot (as I would expect), but on the output side, only hot for a few inches. Definitely not cycling as I would expect.

Has anyone experienced something similar?

Things I think could be failures:
1) Switch not working and telling the valve to open
2) Valve not working hence no fluid movement
3) Air in the system preventing hot coolant flow?
4) Instructions are incorrect and it DOES matter which of those output hoses go to which fitting?

Any way to force the valve open to eliminate that as a possible problem? (I disconnected the temp control knob to see if it would default to "open" but no change in behavior....

Stumped.....
Rian

[Namrups]

Check the heater control rheostat on the dash. My valve was not working either. I checked the rheostat with an ohm meter and found it to be bad. FF sent me a new one that I checked with an ohm meter and is working properly. I have recently installed it but have not had a chance to try yet.

[Rian_Colorado]

So 1 thing that I checked before I called it good for the night - I checked the switch and the valve function. With the motor off, I can hear the valve actuating when I adjust the the rheostat. In my mind that kind of eliminates the rheostat as a possible problem? Given that I can hear the valve turning as well, I'm REALLY thinking that this has to be an issue with flow in some way.... Trying to think of ways to eliminate or check for possible air in the system?
R

[Namrups]

Once the engine is warm try cracking the upper connection to the heater. If there is air in the system you should hear it escaping. With the engine cold, you could also try to remove the heater hoses from the valve. Pour fluid into the upper hose until it comes out the bottom hose. That would also push the air out of the heater core.