Gmt800/900 fan in Gmt400?

[400North]

Blower Motor Resistor Thermal Fuse Replacement

Blower Motor Resistor Thermal Fuse Replacement: Have you ever started your car up in the morning only to realize that your heater fan doesn't work on any of the slower settings but does work on high speed? Well, my friend did. In, fact, this occurrence happened to him not once, not tw…

www.google.ca

Also here’s an article that will help you replace the thermal cutoffs/fuses in a blower motor resistor if you want to. I did it with my broken resistor and it worked (I used 15 amp fuses instead of 10 amp fuses it originally came with just to test with a gmt800 blower motor, but some of the fuses still started to smoke so 20 amp is the next step up I will try).

 

[alpinecrick]

If possible, get early GMT 800 parts. I've got a 99 NBS, and I've never had to mess with blower motor resistor blowing out on that truck.

My brother had an 06 that went thru resistors often. Not sure why. I bought an 04 project SUV, and that was one of the first things I had to change. And my 2000 k3500 GMT 400 also had the resistor blown when I bought it...

Also, out of all those trucks, the 99 is the only one with a cabin filter. Not sure if that's a 99-02 thing, but at some point the cabin filter was deleted. May not matter to you though.

My 01 Sierra has a cabin filter also. I'm thinking it was deleted in 03 models?

 

[alpinecrick]

This is a helluva lot of work to get possibly 1 cubic inch a minute more air volume.........

I know the gen-u-ine GM OEM blower blows more air than the Four Seasons blower in my 02 vs 96 vans, which are identical.

 

[stutaeng]

My 01 Sierra has a cabin filter also. I'm thinking it was deleted in 03 models?

Yes, I believe so, 99-02. I also have an 04 and 06 SUV, and neither of them have cabin filters.

 

[Donald Mitchell]

The airflow problem is in the box itself. It needs to be clean and all seals in place, with actuators functioning.

 

[Dropped88]

The airflow problem is in the box itself. It needs to be clean and all seals in place, with actuators functioning.

Agreed. I've did that to 2 trucks (early&late) and no complaints on the performance afterwards

 

[Orpedcrow]

@Donald Mitchell @Dropped88
I’m fixing to do this job, do you remember what size gasket material you used? It’s cheap but I don’t want 6 different sized rolls of foam tape if I don’t need it lol

 

[Dropped88]

I do not remember what I used. But lmc does have main one for cheap

 

[Donald Mitchell]

@Donald Mitchell @Dropped88
I’m fixing to do this job, do you remember what size gasket material you used? It’s cheap but I don’t want 6 different sized rolls of foam tape if I don’t need it lol

I used 3/4" wide by 3/8" or a little more thickness from Lowes. I had some left but no package.