How to Replace Blower Motor Resistor

[Motorgod0]

Hey all. Sorry in advance if this is the wrong area. If I am then get the ripping out now and direct me to the right place. I’m new and have only replied to a couple things. I have 90 gmc suburban, 5.7 TBI. I have front and rear AC. It blows cool but very weak even on the highest setting. I’ve replaced the resistors, cleaned out debris from everywhere, swapped the blower motor and verified the blend door work. Any idea how to get more air pushing out the vents? Thanks

 

[Tim W]

I found that removing the purple and black wire from the blower motor and bringing it up through the glove box allows you to be able to push the blower speed relay harness back far enough to easily remove the resistor. Even with big hands like mine.

 

[evilunclegrimace]

Here is the switch that you can replace with out buying the entire control head,

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the part number is 16192099 it is for '96-'00 Chevy-GMC control heads that have a part number of 9378815 or 9378805. It will also fit SOME '95 trucks but they must have the new style control head

 

[TBaganATX]

Ok.. so I'm having issues with my AC in my 94 Blazer. Now realizing there are multiple resistors for w/ AC 3 & 4 speed and w/o AC. I have bought all new relays, changed 1 got the other 4 the other day. I changed the resistor, now realizing that it is for a W/O AC, so I ordered a 4 speed AC, plan on changing this weekend. The 2 are a lil different on has 2 prongs and 3 prongs. The new one has 3 prongs and 2 nubs. I'm guessing the 2 wire will some how connect to the nubs? Also, noticing that my AC speed switch will go 3 speeds and barley puts out air, even on high. Now when I can get it to switch from low/med and med/high the air really starts blowing much harder, then switch to High and blows as it should. Then it will just completely, shut off. There is either a short or something I'm missing. Anyone have any suggestions besides lighting a match?

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[Tim W]

I got my 4 speed one from LMC. Its the only one that has worked worth a dang

 

[TBaganATX]

I got my 4 speed one from LMC. Its the only one that has worked worth a dang

Tim, you got a 4speed resistor? I bought mine from Rock Auto and tempted to return it.


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[Tim W]

Yes sir. The 4 speed. I got several from auto parts stores that kept going out. Im not so sure they gave me the 4 speed one. This one has been going now for a while

 

[Tim W]

This one to be exact

https://www.lmctruck.com/1988-98-chevy-gmc/cd-1988-98-heater-components

Its #7 the one for the 94

 

[HotWheelsBurban]

Here's what happened on my first 99 Burb. The blower got to where you had to kick it or slam the door to make it come on, then when you hit a bump in the road it would go off again. Ended up replacing the blower motor, the resistor and the control switch in the dashboard. Apparently the control switch is a common problem for the 95 up trucks. Had to replace it 3 times on this truck. Probably going to have to do all this on the current Burb, just haven't gotten around to it yet. Got to see to several different things in the dashboard

 

[Eveready]

Ok.. so I'm having issues with my AC in my 94 Blazer. Now realizing there are multiple resistors for w/ AC 3 & 4 speed and w/o AC. I have bought all new relays, changed 1 got the other 4 the other day. I changed the resistor, now realizing that it is for a W/O AC, so I ordered a 4 speed AC, plan on changing this weekend. The 2 are a lil different on has 2 prongs and 3 prongs. The new one has 3 prongs and 2 nubs. I'm guessing the 2 wire will some how connect to the nubs? Also, noticing that my AC speed switch will go 3 speeds and barley puts out air, even on high. Now when I can get it to switch from low/med and med/high the air really starts blowing much harder, then switch to High and blows as it should. Then it will just completely, shut off. There is either a short or something I'm missing. Anyone have any suggestions besides lighting a match?

Just noticed this one. Most likely this is a blower motor issue. The fact that it will run for a while on low and or medium and then quit after running on high suggests that something is overheating or opening when the motor heats up. Most likely a bad bearing is dragging. Suggest the usual blower motor replacement and heater core cleaning while it is out. If you have fixed it please let us know what you did, if you do fix it please report back to the thread and update how it happened. Good luck !