HVAC Blower Motor Resistor Wiring ?

[JCoffey]

I was driving my '06 tonight to dinner with my wife with the AC running and the fan motor on the second to lowest speed position. We are pulling in to the restaurant parking lot when she comments that something has burned her foot from under the passenger side dash and asks me what may be under there that could have done it. I tell her that the blower motor is located under there but it should not have burned her. We park and I come around and look up under the dash and see two wiring connectors in the motor vicinity. One looks to go to the motor and the second is there fairly close to it and is so hot you can barely hold on to the wires going in to the connector but I do not know what these do. We go on in and eat and come back out and I check them and they are cooled down. We start home and I turn on the Ac as before and have her reach down and feel the wires as we travel and they are starting to get very warm again. I turn it off for a few minutes and they cool down. I try it again with the fan on but the AC off and they start heating up again so I have narrowed it down as to not be a strictly AC problem but a motor on/off problem. Drive the rest of the 20 miles home with no fan and the windows down in the 100 degree weather. ( Yes I am a bit spoiled but that is why I have AC. )



Get home and start looking at my FSM and determine that the wires getting hot are going in to the blower motor resistor assembly which gives the motor it's different speeds based on switch position. Manual says that the blower motor resistors can get HOT during operation and says to check for continuity between all of the terminals on the assembly. I will remove this and check for the continuity tomorrow. My question is has anybody else ever noticed this hot wiring going in to the assembly and should the wiring be getting so hot that you can barely hold it? It doesn't seem like it should be to me.



Let me know any thought ya'll may have on this.



Thanks,



James

 

[B.G. Smith]

The resistors mounted to the inside of the resistor block get very hot, (this is normal) especially the lower blower motor speeds, that is the reason it is mounted so the resistors are inside the AC housing in the airstream. The wires would get some heat soak from ther block but should not get hot enough for something to fall off and burn someone. However, the resistors have been known to get hot enough to start a fire in the AC housing if leaves or any combustable material builds up inside and come in contact with the resistors. You may have a bad connection where the wires plug into the block or even a defective resistor block. I would remove it and see what the resistors look like and check the connectors where it plugs in. bg

 

[JHardwick]

The blower motor is soon to fail. Maybe pull it and blow the squirrel cage off to reduce drag, but it should not be hot.

 

[Bob4x4]

There is a heavy duty resistor available that will increase speed in all positions. I would guess less reistance less heat. Part# is 68004539AA. I am not sure of the range of years it will retrofit to.

 

[jsdan]

Bob 4x4, will this HD resistor increase fan speed to blow harder?



Would like to know if this would work on my 06 Mega cab.