HockeyFan999

I just purchased a 1992 F-150 5.0 with 215,000 miles on it. I noticed on top of the heater box (inside engine bay, passenger side, near where
the heater core hoses connect) there is some type of switch with a vacuum diaphragm on it. I assume it is to close off the water from going to the heater
core when using the air conditioning or vents. Mine is not connected to anything. I am not sure if there is a wire going to it or a vacuum line. Can someone tell me what and where it connects to?

Thanks

Steve83

That's a vacuum "motor" or actuator. Click these & read the captions:


(phone app link)


(phone app link)


(phone app link)

HockeyFan999

OK someone had cut the white vacuum line right at the end of the tape in the harness, I was able to locate it, and connect another hose from
there to the vacuum motor. Now after I change the heater core, I will troubleshoot some more.
Thanks for the diagrams!!!!

JUNK-MAN

Mine was rotted off...i fixed it with weedwacker gas line.