No Heat

I have no heat just cold air when control set to heat. Note: the control does not move smoothly from cold to hot and back, it has a 2 spots that it likes to set in as you turn it. I'm not sure if this could be the problem. I would appriciate some comments on how to start to narrow the problem down, since it could be the thermostat linkage, or heater box related, or the termostat it's self.
Thanks.

i think that it is either the heater core or the thermostat. if your temp doesn't get very high very fast in the winter then your thermostadt is stuck open. that will cause it to be cold.

is there a fuse for the heater that you know of?

Check your heater hoses to the core, are they both hot? if outlet is cool -core is plugged. Missed what year your truck is? is heater control cable or vacuum operated? check heater control valve to see if it is opening.

I agree with trukasaurus. I doubt its the thermostat, I have know people that actually didnt have one in and they still got heat. One more thing, does the truck have airconditioning? If it does it will be a breeze to change the heatercore and they cost 37.00 and some change. But do it yourself, a shop will tell you it will take a hour and a half to fix {shop books are usually a little high} but I got mine in and out in under a half hour. Good luck and keep me posted on how it went.

I have no heat just cold air when control set to heat. Note: the control does not move smoothly from cold to hot and back, it has a 2 spots that it likes to set in as you turn it. I'm not sure if this could be the problem. I would appriciate some comments on how to start to narrow the problem down, since it could be the thermostat linkage, or heater box related, or the termostat it's self.
Thanks.

My 99 f150 has the same problem with moving the temperture selector knob. Worked fine until I had the radiator flushed. Then every morning it will not move smooothly or change the temp setting. After running 30 min. or so, it's fine, works just as expected. The next morning it's back again. Did you ever find the trouble with yours?
Thanks. Ken

My 99 f150 has the same problem with moving the temperture selector knob. Worked fine until I had the radiator flushed. Then every morning it will not move smooothly or change the temp setting. After running 30 min. or so, it's fine, works just as expected. The next morning it's back again. Did you ever find the trouble with yours?
Thanks. Ken


I finally found out the problem.....it was the selector knob...it was slightly striped and that is what caused the movement and also that is why it did not get full heat...

I replaced it and it works perfect now... who would of figured?...

Thanks for all the help anyway.