He blower motor cuts off at the max (5) setting?

Tiny
ECUELLO
  • MEMBER
  • 2005 CHEVROLET TRAILBLAZER
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 64,000 MILES
I recently replaced the blower motor resistor and the resistor connecter due to the blower not working at all. Now the blower motor cuts off at the max (5) setting. I back probed the blower motor connection and I have voltage and it switches all the way up to 4. As soon as I set it to 5, the voltage drops and the blower motor cuts out. I also replaced the heater/ac control module thinking that was the only possible solution but it still cuts out. Both Contol modules (old one & new one)cut out on the max setting. I have also tried 3 different resistors and still have the same problem. Any direction given will be greatly appreciated.
Tuesday, December 8th, 2009 AT 6:27 PM

9 Replies

Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Try checking the 40 amp fuse at the under hood fuse panel, here is the fuse location and a guide to help check it.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Here is the blower motor wiring diagrams so you can see how the system works. Check out the diagrams (Below). Please let us know what happens.
Images (Click to make bigger)
Thumb
Thumb
Thumb
Thumb
Was this
answer
helpful?
Yes
No
Tuesday, December 8th, 2009 AT 6:33 PM
Tiny
ECUELLO
  • MEMBER
  • 6 POSTS
By HVAC control module do you mean the actual unit that you can select speeds? The manual says that the blower motor relay is on the blower motor housing; can't find it. Help!
Was this
answer
helpful?
Yes
No
Tuesday, December 8th, 2009 AT 9:18 PM
Tiny
ECUELLO
  • MEMBER
  • 6 POSTS
By HVAC control module do you mean the actual unit that you can select speeds? The manual says that the blower motor relay is on the blower motor housing; can't find it. Help!
Was this
answer
helpful?
Yes
No
Tuesday, December 8th, 2009 AT 9:24 PM
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Blower Motor Resistor Assembly Below right side of dash, near blower motor-sorry no pic's
Was this
answer
helpful?
Yes
No
Tuesday, December 8th, 2009 AT 9:24 PM
Tiny
ECUELLO
  • MEMBER
  • 6 POSTS
By HVAC control module do you mean the actual unit that you can select speeds? The manual says that the blower motor relay is on the blower motor housing; can't find it. Help!

Already replaced blower motor resistor three different times thinking that they were defective.
Was this
answer
helpful?
Yes
No
Tuesday, December 8th, 2009 AT 9:26 PM
Tiny
ECUELLO
  • MEMBER
  • 6 POSTS
Already replaced blower motor resistor three different times thinking that they were defective. Can anybody tell me where to locate the blower motor relay?
Was this
answer
helpful?
Yes
No
Wednesday, December 9th, 2009 AT 10:48 AM
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Try this: so much of auto references misdirections

Check in the underhood fuse block -see below Itme NO.1 for location of relay


https://www.2carpros.com/forum/automotive_pictures/12900_relay_1.gif

Was this
answer
helpful?
Yes
No
Wednesday, December 9th, 2009 AT 10:57 AM
Tiny
ECUELLO
  • MEMBER
  • 6 POSTS
Replaced relay; checked all fuses, blower motor still cuts out when max speed is selected.

Is there a procedure for recalibrating the HVAC control module?

What other trouble shooting can I do?
Was this
answer
helpful?
Yes
No
Wednesday, December 9th, 2009 AT 3:37 PM
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Did you check the wiring from the diagrams above? You must have a broken wire.
Was this
answer
helpful?
Yes
No
-2
Wednesday, December 9th, 2009 AT 3:54 PM

Please login or register to post a reply.

Related Blower Fan Resistor Content

VIEW MORE