Ford blower motor resistor problems remain the most common solution to interior fan malfunctions on Ford cars and trucks. With that said, failed blower resistor assemblies don't solve all of the possible failures. This is why at the bottom of the article we include a 2008 F150 blower motor wire diagram.
The interior fan is powered by two separate fuses and a blower motor relay. The HVAC circuit is controlled by a switch. On the automatic temperature control system they further complicate the system by using a module. Malfunction of these components can cause different symptoms and that's where we’ll start.
First we'll cover the most common symptoms associated with a bad Ford blower motor resistor. Next, we cover …show more content…
Whether you have a blower motor problem on a 2009 Ford escape, 2004 Ford F150 pickup truck or even an Expedition or Mercury mariner these blower motor control systems use the same parts. In addition, the wiring diagrams and the circuit operation also remain very much alike. However, the [[Ford Fusion blower motor resistor]] is a completely different animal.
Card Type Blower Motor Resistor
The thin card type Ford blower motor resistor is the most common part used for the interior fan speed control. It fits almost all of the truck and sport utility vehicles like the Ford Escape, Expedition, Explorer and Lincoln Navigator from 1999 through 2012.
I'm also pretty sure this is the same part used in the Ford Crown Victoria. When this resistor module fails drivers often complain about losing individual blower motor speeds. Sometimes you will only have low and high speed settings. However, the most common complaint when this part fails is that only the high speed setting functions.
If you look at the wiring diagram for the Ford F150 below, you'll see that the high speed setting bypasses the resistor assembly completely. I'll go one step further and say that if you're blower motor works on high and you have the card type Ford blower motor resistor, no further diagnosis is