Howdy!

Picked up my truck back in the colder months. It overheats now that it's warmer. Radiator is in great shape, t-stat opens when it's supposed to... Missing heater control valve under hood. I pinched the heater hose off with some needlenose vice grips, and I haven't been able to get it to overheat again. The truck is missing a heater control valve that I can see. It is a non ac truck, and there doesn't appear to be any valve whatsoever under the hood to block the flow of coolant to the heater core.

I've found the vacumn controled heater valve online, my only problem is I don't have any vacumn switches in my climate control panel... just a cable for defrost or floor, and a cable that opens the "blend" door. The only vacumn line I have under the hood goes to the spark advance canister on the distributor. I'm having a heck of a time finding any diagrams that show how the valve is supposed to be set up.

Thanks for any help!
1973 F100
302
power.... nothing
3sp