Fan motor only runs on high setting

[frank1]

On may 03' Quad cab, the fan motor only runs on the high setting both on A/C and heater. Bad fan motor? Thanks for any help, Frank

 

[MLee]

Might be that the relay needs replaced. High speed is an indicater.

 

[TLane]

If the motor runs on high, then the motor is probably good. I'm not certain on an '03 Dodge, but typically the fan speeds are provided by a set of resistors. On high, you get 12v straight to the motor, on the next speed down it goes thru the first resistor, on the second speed, it goes thru another resistor, and so on. The resistors are typically wire coils inserted in the air stream just down stream from the fan. Look for a connector with four or five wires going into the air stream.

Hopefully someone can give you specifics on the Dodge.

 

[frank1]

Thanks Tlane, I'll look for the wiring this week- Frank

 

[MCherry]

Had this problem on my '01 and it turned out to be the resistor. It's a fairly easy job to change it out. If you have, or can look at, a service manual that will make it easier.

 

[B.G. Smith]

Hey Frank, yeah, TLane is on the right track. YOu should find the resistor block on the bottom of the AC housing under the glove box. Held in place by two screws. Mine cut out on low and it turned out to be a bad connection at the resistor, cleaned it up and all is well so far. (check the plug in connections at the resistor first as the resistor block is around 60-70 bucks) bg

 

[frank1]

Thanks for all your input, I just ordred a service manual from Geno's Garage. I thought it would be wise to, especially owning two 03's. Should have it in a couple of days. Thanks again, Frank

 

[WMoroni]

Try tilting your steering wheel up and down pretty hard and fast and see if the fan comes back on with it on low. If this works it has a bad key switch.

 

[frank1]

WMoroni --- trying tiliting the steering wheel fast and hard, no luck, must be the a resistor. Thanks Frank