my blower motor only works on the high and setting before high dont know if it needs switch or what does not work on low

 

Blower motor resistor.

 

This happend to my grandpa's Super Duty. It's the blower motor resistor.

 

I have the same problem. Last week fan only worked on hi. Replaced resistor, back to normal. As of today only works on hi. Within a week part went bad. What caused this resistor to go bad within a week? Is it a bad switch?

 

i thought the resisitor was only if it worked on high but it still works on 2 settings

 

Mine worked on two speeds. Speed 1 was nothing, speed 2 and 3 were what speed 2 normally was, and 4 was still high.

 

my crown vic fan only works on high.. any parts store should have that resistor right? or is a dealer part??

 

I spent a few years as a mopar dealer mechanic, and this problem was common on the caravans. If the resistor was replaced and then went bad a few weeks later, it was always the blower motor causing the problem. If the blower motor is drawing too much current it will burn out the resistor repeatedly.
Obviously your truck is not a caravan, but the setup for these hvac systems is all pretty similar. Just my two cents, hope it helps.

 

It's a $12 dealer part. I doubt any parts store would have it.

 

your right dealer part only.. just came from autozone and they said couldnt get it.. rockauto is always been good ill try them.

 

I will replace the motor and resistor. I will let you know. Thanks.

 

Im haveing the same problem where is this part located? Under the dash on the passenger side or under the hood?

 

Depends what year and type of truck you have. Mine was under the hood. It looks like the F-150s is under the dash though.

 

2004

 

Go look down in the technical document section, there is a write-up on one there.