Hey guys,

My blower quit working about a month ago, not a big deal as i dont drive it daily or even weekly. None the less, want to get it fixed.

First thing i did was tried a new fuse, blew another one right away

2nd thing- bought a new blower and changed that last night. it was toast and most of the way locked up so im glad i got a new one. reason #1 it quit working by the looks of it. (it had made a click noise for a few years, just never tore it apart to see. I thought it was coming from up above on the dash until it went out completely)

After i got the old blower out, i wanted to try the new one. So, i hooked the new one up to the resistor while i had it all apart. Key off on the truck, door open, poof plugged it in and it starts running, looked to be wide open.

The resistor was putting out about 12.8 volts or so with the key on before plugging it in. The scale on the dash at about 1/2 speed. (wanted to see if there was even power going to it before plugging the new blower in.)

Im not sure if the resistor pack is completely bad or if i have a short somewhere. I was convinced it was a resistor but the dealer thought it could be a short as well, when in discussing it while they searched for the unavailable resistor through gm.

now- where my question comes in.
I thought the resistor only bypassed on full speed on the switch otherwise it wouldnt work at all if it was the resistor? I would assume that if it was good, id have less than 12.8 volts at half speed? would these symptoms result from a bad resistor? I hate to buy one if i dont need it, nor do i want to tear my dash apart looking for a short if the symptoms will lead to a resistor failure no matter what.

any help?

Thanks,
Steve

 

The resistor should fix your problem.

 

sounds good, not many of them around any more... no gm dealers have them in stock, no autoparts stores that i found.

found one referbished one online that hopefully they have in stock for me.

are you guys retro-fitting the carquest #RU-1321 by cutting the wires and rewiring in a new one?

steve

 

thanks for the info, the resistor did indeed fix it. although it was quite a project to find one and never successfully found a brand new one, there is a place in cali that rebuilds them. ended up going that route with success at least.

fan is blowing nicely now with all of the proper controls and such.

steve

 

New twist, worked for about 40 miles o. All ranges except high. Turned it to high and burned something up.

Going to tear into it again tomorrow... :'(

Thoughts?
Steve

 

anyone with anything on it? dont want to have to buy another resistor as they are refurb on ebay only, it seems.

anyone know where the wires could possibly rub and short on the frame or something?

what voltages should i be experiencing on different fan speeds out of the resistor?

im hoping it is a fan, but i have a feeling another $70 fan isnt going to fixthe issue im having.

steve

 

Try Ebay?
RU-1321 | eBay

 

I bought this one and replaced both the blower and the resistor last week.

Reman 03 06 Hummer H2 Heater Blower Motor Fan Resistor Control Module Exchange | eBay

cooked something and could smell burned electrical again last night, not sure what though.

Found out that the red from the truck to resistor is always hot, ground is ground, middle wire is from the controller on the dash- digital voltage until it is on high. then it bypasses to go to 11ish volts, this can be a way to test to make sure it is getting the correct voltage to the resistor for the high circ anyway.

on the resistor to fan side, i was told that the red is always hot, ground is variable and controls the fan speed from the resistor.

sounds like i can at least test it tonight to see if i fried the resistor again or if i burned up a fan. im not sure if it has too high of voltage, not sure why it would go really high to burn out the fan either. It didnt blow the 40 amp fuse in the engine compartment, i checked that when i got home last night with it.

i will check all voltages and report back here, as well as checking the fuse inside the cab.

steve

 

well after more testing last night, all looked pretty close but just didnt seem correct.

took the resistor out, it smelt like burned electronics, i guess that is probably a problem LOL

ill report back my findings after i get a new one again next week. the resistor will get inspected, hopefully i dont have a bad head control unit, i dont want to buy one of those too.

steve

 

got the new one in and drove it for a bit, it was running intermittent during the trip. may have some issues with it still... not sure what that could be, maybe it is another resistor i guess.

steve