The valve is a simple vacuum-operated two way valve. It isn't fancy like a servo that opens partially. This one is either all the way on or all the way off.

So, applying vacuum opens the valve, then you should feel heat flowing through the hoses. It's like an electrical switch; if you block flow in any portion of the circuit, the whole thing (both hoses) stops flowing.

It wouldn't hurt to take the valve out and replace it with a short nipple, for testing purposes. BTW, many millions of cars and trucks over many brands used a valve just like yours. Other options include a mechanical arm that operates with a cable or a solenoid valve operated by 12 volts. - Dave

would you happen to have the pages from the shop manual on the vacuum lines to help me trace them?

You can download a digital copy of the shop manual for less than $20 here. It's cheap considering how much you will use it.


John

Well I got permission from the boss to pull the trigger, 24$ Canadian thanks to it being on sale for 16 (y)

- that section of the manual leaves some to be desired and shows a 3 port manifold with two hoses, but still doesn't answer where the thin hose in my photo goes?

I think that tube is the main supply for the ac/heater vacuum. Should be 7/64ths in size and goes to the cannister on the front fender. I had a problem with my heater and found that that valve was clogged with dirt and rust. Try cleaning it out.
Send me a pm with your email address and I can send you a Vacuum Diagram for 64-65's

Pm'd ya ( .... to reach 10characters )

Diagram sent. That canister is normally for door lock vacuum. AC and heater vacuum for a 66 usually comes from a canister on the front fender just behind the battery or from behind the light.
See link

i have found the other vacuum can and replaced the line to it, added a T back in where it was missing and ran a new line into the cab ( i might have been able to skip that step but i got a little rammy and foolishly pulled the main line out yesterday )



then i removed the blower motor and the thermostatic control valve and replaced the broken thin line, 2moro i need to get another 5/32" T and hopefully finish messing with vacuum lines

stubbie do you mind if i post up the diagrams you shared with me?

I can't remember were I got it. It may have been here on the tech pages.

Hah , I swear I had them printed once from somewhere but they never made it to the garage, but I don't know where I got them from





The 2nd T of line B is not representative of where it actually is in the car ( it's actually way down in the center console ) the first T is accurate as it's behind the dash right at the firewall

Well I hope I never see this part again, what a pita to get to then remove and reinstall, good news is I now have heat! While I was fiddling with it I found the supply line for the rear vents laying cut off in the engine bay, after a trip back to town for more hose and another T ( I got two this time and we went to Taco Bell for dinner haha) Ive got it reconnected. I'll test it 2moro after I drop my daughter at daycare

Cody, I'm glad your car is shaping up for you. Replacing all the vacuum hoses is smart as you can see in your 'travels', errors and mistakes that simply show up along the way.

You're going to be smiling ear to ear when all this starts working again. Oh BTW, I received your CVR money through PayPal. Thank You so much. I've been tempted to visit you but I don't want to drop in unannounced. We're only about an hour and a half apart.

You're a smart young man, not afraid of the unknown, you dig in and fix your problems. For that I respect you a lot. After it's done, this Thunderbird will be known as Cody's restoration because it represents a part of you that is in it.

Canada is just one mile across the Detroit River but even so, parts are more expensive and more rare; the money has an exchange rate and our border isn't as free as it used to be because of Homeland Security. You overcome these obstacles while raising a young family. Keep plugging and keep us posted because we Squares (as Randy puts it) love helping restores like you. Go Wings! - Dave

Thanks for the kind words Dave, diving into things like this sure is easier for me with helpful people like yourself just a few keystrokes away. I've worked a bunch on my racing motorcycles and like to build things from wood and metal ( my grandpa was a carpenter and built the house I grew up in, I also went to school for welding before I hired on the railway. I didn't take auto in highschool but I'm learning a lot about old cars as i go and I know lots of guys at work if I get into motor trouble shooting as that's an area I'm very green ) I'm on two weeks vacation starting yesterday, and we don't have any major plans ( we were considering vegas but we bought the Bird instead, maybe next year ) when are you free?