Heater problem

[RedFlareside4X4]

My Truck developed a problem with the heater today,it will not blow heat unless the switch is on the High Setting.Has anyone else had this problem?
the truck is a 03 F150 with A/C.
Any help would be great.
thanks

[SKRWZ]

Do you have the dial heater control knobs on it?.... if you do pull the one off that goes from hot to could and look at the back side of it they were prone to crack and break


BTW welcome to fordtough.ca

[RedFlareside4X4]

Do you have the dial heater control knobs on it?.... if you do pull the one off that goes from hot to could and look at the back side of it they were prone to crack and break


BTW welcome to fordtough.ca

mine has 3 knobs ...one controls hot and cold air,one is for A/C and heater ,the other one has 4 Fan setting's from lo to Hi.i can feel the knob clicking on each setting but the heater only blows hot air on the Hi setting.but i will pull the knob off and check it out.
Thanks

[Fordwheeler]

I had the same problem in my 99 350 and it was the resistor, cheap fix.

[SKRWZ]

sorry :icon_cry: I must have read this post wrong :icon_rolleyes: like Fordwheeler said it does sound like the resistor

[Oreo]

I had the same problem, I didn't have low and medium for a while then I lost high. It's in the engine bay.

[RedFlareside4X4]

what was wrong in the engine Bay?

[Fordwheeler]

I think Oreo meant that the resistor is in the engine bay?

[SKRWZ]

It's located inside the on the passenger side under the glove compartment. Also the blower motor is the same type for all F150 from 1997 to 2003. You will see a plug with some wires on it. Thats the resistor remove the two screws (7mm I belive) that secure to the heater box and remove it



http://i15.photobucket.com/albums/a358/Sportruk1/What%20Ever/Picture017.jpg

[Fordwheeler]

Yup thats it, but mine (99 350) is under the hood.

[RedFlareside4X4]

It's located inside the on the passenger side under the glove compartment. Also the blower motor is the same type for all F150 from 1997 to 2003. You will see a plug with some wires on it. Thats the resistor remove the two screws (7mm I belive) that secure to the heater box and remove it



http://i15.photobucket.com/albums/a358/Sportruk1/What%20Ever/Picture017.jpg
thats the baby,i bought one today..i think its in a tight spot to get at but i'll go at it tomorrow.
Thanks for all the replys

[04STXHERITAGE]

Mine seems to 'surge', for lack of a better word, when it's on 'load' something goes clunk clunk clunk, very fast, like the motor is loose, it only happens when it's on cool and heat when there is a 'load' on both and gets louder the longer the truck runs. If I leave the heater on, no matter what speed, turn the truck off, leave it, turn the truck back on, just for a minute as everything starts you can really hear it, sometimes I think it's the 'door' opening and closing real fast? Could it be a bad resistor? sending to much current to the motor causeing it to surge like that when under a load?
I have it to 3-4 times at the dealer for them to look at it, they keep saying it's supposed to do that. I tell them the last 3 trucks we have had, have never done that, or have been that loud!

[Oreo]

I think Oreo meant that the resistor is in the engine bay?

Thanks Sean.

[Firstonraceday]

I also have the same problem, ill replace the part and see if it works. Does anyone know if i use a ohm meter on it what a broken one will show so i know thats the problem?

thanks in advance

[adrian00xl]

yep resistor for sure just did it on my 2000 f150 works like new now