Does anyone know if this is an issues with the temp/heater cluster in the dash, or possibly a heater blower motor issue? Thanks! Ed

 

Not sure about our F150's, but I just changed the Fan Blower resistor pack in a Ford Contour. It probably is a similar issue. The resistor pack dissipates the electrical energy into heat for all the lower fan speeds except high. When the resistor pack goes bad the only speed that works is high. Most of the time the resistor pack is mounted under the dash in an area that will get air flow to remove the heat that gets generated. On the Ford Contour it was located under the glove box and was mounted into one of the air vent ducting passageways, like a small door held in with one screw, about 2" x 3" in size. Hope this helps.

 

Blower resistor, here's how to replace it:

https://www.f150online.com/forums/ar...emtc-hvac.html

 

Awesome! I'll let ya know how things went when I get the new blower resistor installed.

 

Replaced the resistor pack in about 4 minutes. I now have all my fan speeds for the 1st time in over a year!!! Thanks guys! Ed

 

Same problem with my '03 with 115.000 miles. Replaced the resistor with new but no change. Still getting only high fan speed........

 

Assuming a manual control, check the connector at the fan switch as well as the switch itself.