Question about heat

[dburton07]

I have a 93 3.0 w/o a/c. everytime that i put the slider on "off", and the dial on "off", it still blows hot air out of the panel vents. is somthing wrong or does everyone elses truck do that?

 

[pillen140]

turn the fresh air knob to internal air.

 

[koda6966]

....theres a fresh air knobb?

haha

 

[Mark_88]

Mine has them too...they're called window winders...

But some cars have the fan on all the time...you have to turn the heat slider to the cool position on some to stop them from blowing heat in warm weather...

 

[Mark_88]

turn the fresh air knob to internal air.

Does that actually shut the fan off or just give you cooler air???

 

[dburton07]

i always keep it on defrost anyways, but i was just curious if i was the only one. thanks though.

 

[dburton07]

turn the fresh air knob to internal air.

i dont have that, i just have panel, floor, defrost etc. and off low med high, thats it, no internal or external but when both switches are off, it still blows air when the trucks moving, but when its stopped im pretty sure it doesnt blow air, i can tell you which yet cuz its still cold here in maine so i always have the heat on lol

 

[pillen140]

Does that actually shut the fan off or just give you cooler air???

some of the older ones had em, they move the intake air for the heater from inside the cab to fresh outdoor air. if you set it to fresh air, while driving, it will constantly force air through the heater core and through your vents, its like heat, without the fan on. it has nothing to do with the fan though. did you guys think i made that up?

 

[pillen140]

i dont have that, i just have panel, floor, defrost etc. and off low med high, thats it, no internal or external but when both switches are off, it still blows air when the trucks moving, but when its stopped im pretty sure it doesnt blow air, i can tell you which yet cuz its still cold here in maine so i always have the heat on lol

sounds like your mode door is stuck open. at least put the slider to blue, not red.

 

[dburton07]

thats all i got. putting it on cold doesnt mean anything during the summer since i dont have AC. but obviously when i do it right now with the current weather, yea itll blow cold air. its just when both things are off.....is still blowing air

(i could have taked a picture of it, buuut i didnt feel like going outside right now, all i got on is sweats...if youre a college kid, you'd understand lol)

 

[pillen140]

in the summer, put the slider all the way to blue.... this will stop it from blowing hot air, it will still blow outside temp air though. also put it to off, not defrost! off will shut the mode door!!!!!!

 

[dburton07]

no thats the problem im having, when its off on both knobs, its still blowing air through the vents, in the summer when its on the blue, its doesnt blow cold air, but it obviously does in the winter because its cold out

 

[pillen140]

the vacuum piping that controls the mode door could be cracked, not allowing it to change, or it could be jammed? or the control rod could have come unhooked.

 

[Mark_88]

Yep, sounds like the door to allow fresh air in is being kept open...unless you're getting too toasty with it blowing warm air I'd just leave it in the On/Heat position at least until you can crawl under the dash and check the connectors to the door...

I don't envy you...

 

[TrexMex]

I happen to have the exact same problem in my '94.... I'm kind of confused... If I understand this correctly, when everything is turned off, and the selector switch is all the way to the cold (far left) position, will the vents still blow hot air when the truck is moving? I started having this problem this past winter and I had hot air -not cold- blowing through the vents.. didn't bother me too much then but now that's 80 degrees outside at night its a little uncomfortable to say the least... How hard is it to check the heater core door to see if something broke there? If indeed something is broke in there, how hard would it be to fix? I didn't know it was vacuum actuated, my first thought was that it was just a spring-cable setup....