Hey guys.

So I have a 2005 F250 with a 6 L

manual climate control

only low and high on my fan speeds have worked for a long time but recently they stopped working altogether. I had found out that the fan control switch on the backside was melted along with the pigtail. So I replaced the pigtail and the switch and I also replaced the resistor. The blower motor itself I had replaced a few months ago. After replacing the resistor, and the pigtail and control switch today, all fan speeds worked for about five seconds, and now I only have low and high fan speeds again. What do i look for next?

 

Sounds like you have some high resistance somewhere in the circuit. Are all terminal connectors clean and free of crusties? Any wire damage? Signs of critter chewing? I would measure for voltage drop between different points in the circuit to locate the problem area.

-- Dave

 

All wires look clean. Behind the dash i don’t see any damage, and from the resistor going towards the firewall, all those wires look fine. No crusties anywhere.... i don’t know what’s going on. Pigtail at the switch is new, along with the switch. the pigtail at the resistor is new also. Along with a new resistor

 

Common issue, check the corrosion on the connections to the resistor on the blower motor.

 

All connection points are new. No corrosion anywhere. New blower motor, new resistor, new resistor pigtail, new fan switch, new fan switch pigtail

 

I"m thinking blower motor drawing more amps, On it"s way out.