Climate Control Module No Power

[kaiokenkai]

I have a 2003 z71 Tahoe and my climate control module stopped working (but backlights work as shown in picture). Replaced module ( and tested with 2 other working modules ) no fix , checked fuses, and also replaced blower motor resistor. Anyone else run into this issue or have ANY clue on what this could be ? Any information will be appreciated.

p.s the picture is from another guy i found that had the same problem, but was a dead end thread. same exact issue though.

 

[Joseph Garcia]

@swathdiver may be able to give you some troubleshooting pointers.

 

[Fless]

The backlighting is a separate circuit.

Which fuses have you checked? Do you have voltage to the HVAC controller connector, and ground, at the plug on the back?

Interior fusebox on the driver's side by the door:

Underhood fusebox (in addition to the fuse indicated, check the "RR HVAC" fuse that's next to the Starter relay, just to rule it out):

 

[Sanchize6]

I have a 2003 z71 Tahoe and my climate control module stopped working (but backlights work as shown in picture). Replaced module ( and tested with 2 other working modules ) no fix , checked fuses, and also replaced blower motor resistor. Anyone else run into this issue or have ANY clue on what this could be ? Any information will be appreciated.

p.s the picture is from another guy i found that had the same problem, but was a dead end thread. same exact issue though.

What was the solution to your problem?

 

[Fless]

What was the solution to your problem?

We have no idea; the OP hasn't been on here in over a year.

If you have a similar issue, you could provide some vehicle and symptom specifics for the members to ponder.

 

[bluekenworth]

We have no idea; the OP hasn't been on here in over a year.

If you have a similar issue, you could provide some vehicle and symptom specifics for the members to ponder.

2003 gmc yukon denali, very new to me, was doing some work and had the battery go dead, auto climate control module was working just fine before and now everything functions normally except the backlights and the screen dont work.

i tried a unit from the salvage yard (not sure it actually works) and same issue, ive checked all the fuses including the tbc fuses, I have 12volt coming into module and good ground, the only thing i can find is the 5 volt refrence wire on the blue plug is reading 10+ volts,

hoping somone might have the wiring diagram to trace the line and see if there is a short, but seems weird that all the controls would work. i dont know much about the 5 volt refrence system but thoughtit would cause more issues with setting temp or changing actuators

also if anyone knows if any pins are specifically responsible for back lights and screen power besides B7 (battery positive voltage), like what voltage i should be getting on a7 (instrument panel lamps dimming control)

 

[Fless]

So, the automatic HVAC with the digital display.

Does the backlighting work on the instrument panel cluster and on the auxiliary HVAC controls on the overhead console?

Is the instrument panel dimmer pot on the dash control turned up to the detent?

 

[bluekenworth]

why is it always the simple things, my dimmer was as low as it could go, I had just assumed it would always keep the screen on a little.

Thank you very much saved me a lot of headaces lol,