Front Blower motor issue

[HeavyHoe03]

Have a 2003 tahoe, with digital climate control pannel, front blower motor seems to loose power after the 3rd or 4th start of the day, if it sits off for 30min or so the pattern restarts, have tried 2 new control panels, 3 resistors and 3 blower motor, loosing my mind over this, any pointers?

 

[Fless]

If it's being done in AUTO Mode, do your testing in Manual Mode to see if it works the same way.

 

[HeavyHoe03]

If it's being done in AUTO Mode, do your testing in Manual Mode to see if it works the same way.

It does it in both manual and auto mode also in a/c, vent and heat modes wondering if I could be some kind of bcm issue at this point

 

[Fless]

Then I would probably tap the fan power leads and monitor the voltage that goes to the fan in order to confirm that the fan is or isn't getting the power to run. When using the links below, verify your vehicle info and navigate to the similar section for yours.

Harness pinout:

HVAC System - Automatic — 2003 Chevrolet K Tahoe 4WD V8-5.3L VIN T Service Manual | Operation CHARM

Detailed repair manual for the 2003 Chevrolet K Tahoe 4WD V8-5.3L VIN T.

charm.li

Blower motor resistor pinout:

Blower Motor Resistor Assembly — 2003 Chevrolet K Tahoe 4WD V8-5.3L VIN T Service Manual | Operation CHARM

Detailed repair manual for the 2003 Chevrolet K Tahoe 4WD V8-5.3L VIN T.

charm.li

Circuit diagram:

HVAC Diagram 1 — 2003 Chevrolet K Tahoe 4WD V8-5.3L VIN T Service Manual | Operation CHARM

Detailed repair manual for the 2003 Chevrolet K Tahoe 4WD V8-5.3L VIN T.

charm.li

Might make sense to check the fuse pin tension on the fuses that are used for the HVAC system.

 

[HeavyHoe03]

Then I would probably tap the fan power leads and monitor the voltage that goes to the fan in order to confirm that the fan is or isn't getting the power to run. When using the links below, verify your vehicle info and navigate to the similar section for yours.

Harness pinout:

HVAC System - Automatic — 2003 Chevrolet K Tahoe 4WD V8-5.3L VIN T Service Manual | Operation CHARM

Detailed repair manual for the 2003 Chevrolet K Tahoe 4WD V8-5.3L VIN T.

charm.li

Blower motor resistor pinout:

Blower Motor Resistor Assembly — 2003 Chevrolet K Tahoe 4WD V8-5.3L VIN T Service Manual | Operation CHARM

Detailed repair manual for the 2003 Chevrolet K Tahoe 4WD V8-5.3L VIN T.

charm.li

Circuit diagram:

HVAC Diagram 1 — 2003 Chevrolet K Tahoe 4WD V8-5.3L VIN T Service Manual | Operation CHARM

Detailed repair manual for the 2003 Chevrolet K Tahoe 4WD V8-5.3L VIN T.

charm.li

Might make sense to check the fuse pin tension on the fuses that are used for the HVAC system.

thank you, i have checked fuses, they seem good and tight, have also tried different relays aswell

 

[HeavyHoe03]

thank you, i have checked fuses, they seem good and tight, have also tried different relays aswell

the only other thing that could be an issue but im not sure is, my ignition switch has a little bit of play in it, key needs to be jiggled to get it to turn over sometimes, could it possibly not be sending control voltage to something?

 

[Fless]

I don't see any relays involved. If you're going to troubleshoot this you'll need to use service info and a good DVOM. Probe the fan power/ground feed as noted before to determine if power or ground (which one, if any) is not present when it should be. Follow the data.

If the fan ground is missing when it won't blow, the ground for the HVAC blower is G200, shown in the link below.

G200 — 2003 Chevrolet K Tahoe 4WD V8-5.3L VIN T Service Manual | Operation CHARM

Detailed repair manual for the 2003 Chevrolet K Tahoe 4WD V8-5.3L VIN T.

charm.li