Climate Fan Issue

[amurp15]

I first started having real problems with my blower motor fan a couple weeks ago. Was on a 2 hour drive, and the blower got super weak, to the point where you can barely feel the air coming out of the vents on max. Turn it off for 10 minutes, turn it back on, and worked for the rest of the drive with no issues. Come out the next morning and it doesn't work at all. After driving it for a day or two, it just randomly turns on and works like normal, 10 or 15 minutes into my drive. All of the different fan speeds work perfectly, turns off and on when I press the button. So I ordered a new blower motor and replaced it anyway, just to prevent the same thing from happening in the future, and a day or two after I replace it, it stops working again. So its been randomly going in and out for about a week now.

I found some posts about the blower motor resistor, so even though I'm still a little unclear on its purpose, I ordered a new one and its on its way. I took the current one out and looked at it, everything looked like it should but again I don't know what it does. Do you guys think that is my problem or should I look at something else? Thanks in advance for your help.

 

[SitKneelBend]

I first started having real problems with my blower motor fan a couple weeks ago. Was on a 2 hour drive, and the blower got super weak, to the point where you can barely feel the air coming out of the vents on max. Turn it off for 10 minutes, turn it back on, and worked for the rest of the drive with no issues. Come out the next morning and it doesn't work at all. After driving it for a day or two, it just randomly turns on and works like normal, 10 or 15 minutes into my drive. All of the different fan speeds work perfectly, turns off and on when I press the button. So I ordered a new blower motor and replaced it anyway, just to prevent the same thing from happening in the future, and a day or two after I replace it, it stops working again. So its been randomly going in and out for about a week now.

I found some posts about the blower motor resistor, so even though I'm still a little unclear on its purpose, I ordered a new one and its on its way. I took the current one out and looked at it, everything looked like it should but again I don't know what it does. Do you guys think that is my problem or should I look at something else? Thanks in advance for your help.

Is it coming out elsewhere? Could be a blend door issue if the fan speeds are working.

 

[amurp15]

No, I'm sure that the blower motor is not working at all when it goes out

 

[SitKneelBend]

No, I'm sure that the blower motor is not working at all when it goes out

@Mpgrimm2 might have some thoughts on this. He's fairly familiar with how these operate and what may be at fault.

 

[Mpgrimm2]

Is this a factory 8.4 equipped truck or was it converted from smaller base radio setup? (2500/3500?)

If so, when?, what was the original radio/fan speed setup?, what actual parts were used? including where the conversion harness set came from?.

 

[amurp15]

@Mpgrimm2 sorry for the late reply. To my knowledge, this is a factory 8.4