# HVAC Issues: Blower Motor Turning Off Randomly While Running



## Grizz8674 (Apr 26, 2016)

What's up guys? So about 2 months ago I started having HVAC issues with my '11 LT Cruze. The A/C would be blowing like normal and suddenly shut off and come back on a few moments later. It did this 5 or 6 times over the course of a few days before it shut off and wouldn't come back on. I took apart the glove box and dash pieces to get to the blower motor itself to diagnose the issue. Well, once I got down to the blower I turned the fan switch on and to my surprise, it was working through every setting. I left the dash apart for about 4 days just in case it decided to quit on me again and it didn't. I put everything back together and it's worked fine for about 2 months until now. So again, I take the dash and glove box apart, get to the blower and turn the fan switch on and it still won't work. I tested out a few things to find out if I pushed up on the plug itself it would turn on and work like it's supposed to but if I let go of the plug it shut right off. After fighting with the plug for about 2 hours I finally got it out and once I pulled it out I figured out why it wasn't working. The plug connector and the red and black wires about an inch down from the connector were all black and melted together. The end of the connector was completely melted to the plug on the blower motor which was why I couldn't get it out. Long story long, something was shorting out the wiring and melting/burning the connector and wires. The Cruze has a transistor that is supposed to trip with these types of issues, and if the transistor doesn't trip the fuse is supposed to trip. Neither did in my car. From my research, I've seen multiple reports of the same type of issue with the blower turning off randomly or just not working at all and the dealerships seem to just be replacing the blower motors but the issue persists. This is just an FYI to those of you that have or have had this type of issue. *Check your wiring, the last thing you want is the wiring issues to start a fire.* Oh, and I found the replacement wire harness online for about $28. The pics I've attached are for reference along with the part sticker on my original wire harness. 

*WIRE - GM (13263281)*

https://www.gmpartsdirect.com/oem-p...9Y3J1emUmeT0yMDExJnQ9bHQmZT0xLTRsLWw0LWdhcw==


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## Tomko (Jun 1, 2013)

Wow. I don't like the look of that.


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## Rivergoer (Mar 30, 2017)

Excellent work, I wonder what caused the overheat situation? 

Was your cabin air filter changed regularly? If it gets clogged with leaves and debris (common) the motor has to work way harder developing excess heat.

My mechanic cousin went to replace a CAF on another brand of vehicle and found it had clogged so badly there was a baseball sized hole in the filter. He had to spend a couple hours fishing debris and filter media pieces out of the ducting, remove and clean the motor. 

Customer wasn't pleased with the bill. But at least the motor didn't fry or worse yet...a fire.

Thanks again for the post!


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## Grizz8674 (Apr 26, 2016)

Tomko said:


> Wow. I don't like the look of that.


Yeah, me either...


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## Grizz8674 (Apr 26, 2016)

Rivergoer said:


> Excellent work, I wonder what caused the overheat situation?
> 
> Was your cabin air filter changed regularly? If it gets clogged with leaves and debris (common) the motor has to work way harder developing excess heat.
> 
> ...


Cabin air filter was/is clean...I'm hoping it was just a faulty wire harness or at most,a bad blower and not something more serious. Absolutely, anything to help others avoid a car fire, lol.


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## jblackburn (Apr 14, 2012)

Oh wow. Wonder if that's related to the Cruzen fire we've seen circulating around FB 23424872492827x.


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## Tomko (Jun 1, 2013)

The first place I would have looked is the fuse box. Makes me wonder why nothing tripped with that volume of current flowing through that connector.


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## ChevyGuy (Dec 13, 2014)

Grizz8674 said:


> Long story long, something was shorting out the wiring and melting/burning the connector and wires. The Cruze has a transistor that is supposed to trip with these types of issues, and if the transistor doesn't trip the fuse is supposed to trip. Neither did in my car.


Long story short, that's not a "short" - that's a poor connection. In a poor connection, the current is LOWER than normal, but the power is going into the connector instead of into the blower motor. That's why there was no overload trip - because there was no over-current. Your only warning is slower speed, erratic operation or smell.

The same applies to household wiring as well. If you've got lights that flicker - worry.


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## KENSTV123 (Sep 21, 2014)

ChevyGuy said:


> Long story short, that's not a "short"
> 
> Very well stated, I'd add it's the resistance caused by the poor connection that causes all the heat at the connector-in other words the resistance drops the voltage across the connector which causes it to dissipate the resulting power loss across the connection, All connectors will have milliohm resistance--it's when it goes to ohms that things start to melt, gold plating is the best as well as proper metal alloy


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## Grizz8674 (Apr 26, 2016)

ChevyGuy said:


> Your only warning is slower speed, erratic operation or smell.


Other than it completely shutting off, I had no speed issues, erratic operation or smells, that's the more concerning part of the whole issue.


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## ChevyGuy (Dec 13, 2014)

KENSTV123 said:


> gold plating is the best as well as proper metal alloy


Gold is rarely used for power applications. It's usually used for signals.

For power, it's more of a matter of contact area and spring tension.


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## jsusanka (Jan 31, 2011)

Could this be part of the logic that turns down the fan if you get a phone call on the bluetooth and start talking. Sounds like that has gone haywire or something. Just a guess.


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