Does anyone know if a 99 F150 has a heater control valve and where it's located? I could not identify one on my motor. I live in Florida and it has not worked for years but I am headed north for Christmas, and the wife is not crazy about just using blankets.

Also it looks like the heater switch is electronic, is the control also electronic or vacuum?

Thanks for ay help and guidance.

Bill

 

There is no heater control valve, coolant flows through the heater core continously. Temperature is (electronically) controlled by a mode door inside the case that commonly breaks.

 

Correct. It's called the "blend-air door".

 

How difficult is it to get too, and replace?

 

It's up in the dash, next to the heater core. Yes, it's hard to get to. But just because you have no heat doesn't mean there's something wrong with it. The most common heat failure I've seen is from people using radiator stop leak as it can completely clog the heater core. There's electronics inside the duct that controls the door (keeps it from getting TOO hot), there's the dash controls, and the actuator on the door itself. Any one of those things could cause it.

 

A dumb simple thing too, pull the **** off the temperature control switch. Sometimes, it splits and doesn't allow the switch itself to turn.

 

reports say 8 hours, after replacing my heater core twice I have it down to around 6hrs. You have to pull the dash. If you ever change the blend door then do yourself a favor and change heater core while your at it. Side note. Block the wheels and remove the transmission shift cable before removing the dash. I broke my shift cable first time pulling the dash.

 

Thread is 14 years old..........