NEED HELP Blower Motor Runs Continuously

[parrishj1190]

Hey all, first time posting here. I have a 2007 Chevy Trailblazer LT, 4.2L I6. My blower motor runs continuously, even without key in ignition. What possible issues could be at play?

The only blower motor resistor that I could find that would attached correctly was part number 4P1516 (this one has the female attachment that fits my male attachment). Is it possible that the wiring to the blower motor resistor is not the original wiring?

I have added a toggle switch to the ground wire for the time being (it is 100+ degree weather right now). Thank you all for any help/guidance and if there is any other information I can provide, then please ask!

 

[Mooseman]

99.9% likely it's the resistor module. It's a common failure mode with the auto-HVAC in the LT (CJ2).

BTW, it's an I-6, not a V6

 

[parrishj1190]

99.9% likely it's the resistor module. It's a common failure mode with the auto-HVAC in the LT (CJ2).

BTW, it's an I-6, not a V6

I'll try this approach. And yes, I6.. lol thank you!

 

[Dr.Fiero]

And splitting hairs here, but... it's not a resistor. It's the mosfet on the board. It shorts out, which is why the fan keeps running.

If you pop your underhood fuse cover off, look at the back right (assuming you're standing on the side), and pull the J-case fuse. That will kill power to it.

 

[aaserv]

Ive got the same problem but with the rear A/c. I pulled the fuse last year and havent thought about it until now. Wouldnt mind getting it repaired... where should i start?

 

[Mooseman]

Probably the same.issue but in the rear HVAC housing, which you have to rip off the right interior panel. I never got mine working after the rear lines broke and blocked them off. There's a schematic of it somewhere on here. Check the FAQs