So this morning I was driving to school and noticed that my heat in my truck only worked on high and not any of the other settings. What could cause this?

 

Probably the blower motor resistor. It's about $30 and pretty easy to change

 

Broken hose going to the accurater. I don`t think I spelled that right.

 

Could be the blower switch on the controll head they heat up where the plug end connect to the switch and burns the connection.

 

Yea, sorry sounds elec.

 

Definitely the blower motor resistor

 

Not true. My blower motor only ran on the high speed setting. The fan switch connector was melted and the switch itself was burnt. After replacing these 2 items the blower motor runs on all speeds. No replacement of the resistor pack was needed.

 

Yeah those switches have 30+amps going through them, its likely for something to burn out over time.

 

An interesting story to me anyway. On my truck when I found the switch and connector fried I went to the junkyard for a connector. Out of 10 trucks 9 had burnt/melted connectors, the 10th one is in my truck. A really poor design to run that much current through a crappy little plastic connector and switch. The least bit of corrosion or dirt on the connector contacts will spell doom to it.

 

I can't remember what year, but I think Ford had a TSB out at one point of the fan controls smoking or catching fire from that. Allot of cars had the same temperature controls as the trucks did.