if your blower control works all speeds but for med. high, and you change the resistor will this correct the problem?

 

Are you saying it does not work on High?
Usually the resistor is bypassed for High speed. The lower speeds not working could be a resistor problem.

 

When you say med. high, you saying the Medium High (the one with the red arrow in the picture), or are you saying medium and high speeds are not working?

If you meant medium high, then yea, I'd guess the resistor is bad.

 

yes I ment the 1, 2 & 4th positions work, but the 3rd does not.

 

It could be the resistor then.

 

I have no heat on settings 1&2 I figure this is the resistor pack but I can not locate it on my truck. 2005 F-150 i was looking behind the glove box but im not sure where. Help