So today i replaced the switch and the resistor pack in my 2010 ford ranger 4.0L SOHC and the two lower settings still don't work. I have the two high ones now. I only had MAX before the parts were replaced. IS there anything else i can be looking at? The plug and wires look fine on the resistor pack and the switch... Can someone give me any ideas where to look now?

 

PDF Diagram here for 2010 Climate system

Doesn't look like there is an OFF for the blower, so I guess thats the 4 speeds you are talking about.

Low, med-low, med-high, high

The blower gets 12volts when key is on, and is grounded always via the 3 resistors and Black/grey wire

Then the switch controls other Ground connections thru a series of resistors, as you turn switch there is one less resistor to Ground, High is No resistors

If Green/White wire was not connected you would lose med-low, but should still have low assuming the Black/grey wire at the resistor block is a good ground, this wire is only used by and for low.

 

I can only say this, when I had to replace the blower motor on my '90 Ranger I noticed kind of a pig tail that comes off the wires that plug into the blower and goes to some kind of relay or resistor or something. All I know is when only the wires that plugged directly to the blower were connected all I had was High and medium-high. Only when the other plug that goes to the relay or whatever it is was plugged in did all four speeds work on my blower. Don't know if this helps or not, I'm no expert but I'd get out under the hood and if necessary remove the blower and check all the wires and connections out there.