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73-87 Chevy _ GMC Trucks => Interior & Equipment => Heating, Ventilation & Air Conditioning (HVAC) => Topic started by: lilkiduno on January 19, 2016, 10:38:04 PM

Title: 1976 k5 blazer blower motor issues
Post by: lilkiduno on January 19, 2016, 10:38:04 PM
Hey guys,

Okay, so I am getting at my wits end with my blower motor circuit. My blower motor had been making a noise and I assumed the blower motor was going out, it sounded like something was rubbing the squirrel fan while it ran. It was making a noise similar to this when I bought it a couple years back now and replacing the blower motor seemed to be the fix. As much as it had been bothering me I was willing to live with it until spring came around as its been chili and I do not have a garage I could work on it in. Well it has finally died on me, no warning just stopped. Looking through the forums people first tend to ask about the relay and resistor so I just replaced them as the old ones were dirty from what I assume years of neglect. So the relay, resistor pack and fuse are new and I ordered a new dmm as I was quite fond of the unit I lost. Is there a way test the blower without removing it?

Once I get my new multimeter what connections should I check and what readings should I expect to see? I assume is should check power to the relay, power to the resistor pack and power to the blower.

Sorry for the ill grammar and spelling I am typing this on a tablet.
Title: Re: 1976 k5 blazer blower motor issues
Post by: Captain Swampy on January 20, 2016, 08:05:20 AM
The blower motor grounds directly to the cab. Take the screws out and clean them up and/or clean one and the spot under it and install a ground wire. To test it, just touch the terminal with a jumper wire from the + battery post.
Title: Re: 1976 k5 blazer blower motor issues
Post by: lilkiduno on January 20, 2016, 11:07:02 AM
I will have to do this when I get home. They don't allow me to play with wiring at work, just chemicals. Thank You for the suggestions. In this weather they are well received!
Title: Re: 1976 k5 blazer blower motor issues
Post by: lilkiduno on January 20, 2016, 01:42:56 PM
Well I ended up getting some wire from the gas station, sometimes you have to love working in the industrial part of town, after running a jumper wire to the blower motor in it's current state the motor didn't spin, I will check the ground/mounting bolts and retry again after I get off work. Luckily it's warmed up to 29° F without wind.

The blower motor quit working over the weekend before and weather was nice enough that it was a slight inconvenience but it was bearable with a good coat. Monday this week changed my out look all together it was 3° F with a windchill of -10° - -20°.
Title: Re: 1976 k5 blazer blower motor issues
Post by: gunrac on January 20, 2016, 04:56:54 PM
Mine went out in my 85' eariler.......u would think those things would last longer then 30 yrs.
Title: Re: 1976 k5 blazer blower motor issues
Post by: lilkiduno on January 21, 2016, 07:06:03 AM
Well it was without a doubt the blower motor. The rivets that held the two halves together were completely gone. The sad thing is this was a new blower motor last year. If I have issues with this new blower motor I am taking out the 1994 blower motor "upgrade" and going back to the stock replacement blower.

Issue resolved, Thank You all.
Title: Re: 1976 k5 blazer blower motor issues
Post by: bd on January 21, 2016, 09:01:22 AM
It's not the "94 upgrade" that caused the trouble, but the quality of the manufacturing.  The vast majority of service parts are sourced outside of the US.  Some of those parts are very poorly made.
Title: Re: 1976 k5 blazer blower motor issues
Post by: impco lpg on January 27, 2016, 12:52:32 AM
my blower has just packed up, and it started making a noise before it went.  just ordered a new one