Intermittent Blower Motor

masonbid · May 31, 2012

A few days ago I went to put my truck in my garage for the night and when I shut it off the fan wouldn't shut off. A quick search on here lead me to believe it was the blower motor resistor. So I pulled the fuse to save my battery and off to bed. Came into work the next day and down to the dealership near my work I go. The woman helping me found multiple part numbers for me so we ended up looking it up by my vin. Ended up getting PN 89019351 and it cost me a lot more than I was expecting... Could have saved a lot if i would have ordered from eBay. After work I went right at it to install the new part. Soldered the new wires nicely and taped it all up. Tested the voltage on the end connector to the motor and I had voltage. Went to plug it into the motor and the motor won't turn on... By this time, I'm quite frustrated because it's supposed to be a simple install and my time is running out since I had to go. While driving with my so called not working blower, it kicked in! Made me slightly more happy knowing that it kinda worked. Yesterday though, the blower didn't work yet again. So i got back under my dash and pulled the motor and tested all my connections and the voltages again. Plugged it in and the blower spun up while sitting on the floor. Put it back in and it stayed working. But on my way to work this morning it wouldn't work... again....

I have no more ideas as to what it may be except for a finicky motor that may have been damaged from my last blown resistor module. Anyone have an ideas that I may be able to use to try to determine what may be causing me issues with my blower?

j13smiley · May 31, 2012

bad ground someplace?

masonbid · June 1, 2012

I'm not too sure. I've checked the voltages to the connector to the motor and it looks ok to me. The motor itself is just a spin lock and doesn't need any ground. I'm leaning towards the motor may have been damaged from the last resistor module but am unsure what type of damage it may have caused if it's only running intermittently.

00Silverado4x4 · June 1, 2012

The motor itself is just a spin lock and doesn't need any ground

I apologize but could you explain what "spin lock" means?? In an electrical system there will be a ground somewhere, even if it's a bolt down (case grounded) component.

masonbid · June 1, 2012

When i was trying to remove the motor i was stumped bc i couldn't locate any bolts to hold it in but i read somewhere that the 06 sierra has a spin in motor. I was able to move the motor back and forth slightly but couldn't figure our how to get it off. When i contorted my body to look underneath it, there was a little tab that you can push out of the way to allow the motor to spin and just come out. What I could best describe it as is like one of the medicine bottle where it locked into place when you spin it far enough.

rolo_az · June 15, 2012

Here's my 2 cents, but it's based on my old 1990 1500. Blower wasn't operating in the different speeds. I reviewed the manual (I actually have the HELM books on this truck ) and it gave me the troubleshooting steps.

I replaced the blower motor & squirrel cage; then all three relays and the thermositor and still the same issue. I traced the electrical diagram to a molex connector. I found that connector under the radio. The molex was melted so I got intermittent connection when it got hot.

I went to Fry's Electronics and got a molex connector that had the same amount of connections and proceeded to replace the bad one.

I had a little trouble with the length of the wires and trying to crimp on the new male/female connectors, so I chose to lengthen both sides with splice/solder/heatshrink. I snapped the connectors in and everything was great. Now I wish I still had that truck.

I hope this might help someone with a similar problem.