RE: Blower motor resistor for fan speed control?
It's definately the resistor...I just had to change one out on my Wrangler.
I haven't had to find it yet on the Ram, but according to the service manual:
The blower motor resistor is mounted to the bottom
side of the HVAC housing near the blower motor.
It can be accessed for service from underneath the
Find the blower motor and there is a wiring harness going to the resistor just to the bottom right of the blower motor. The resistor is held in with 2 screws. It may be easier to remove the resistor before messing with the wiring harness. Sometimes it's tough to figure out how to release them when looking upside down. It also will help if you have the new one so you can see what you're looking for.