HVAC Buttons backlight no longer works

OK, another headscratcher for you guys...I have a 2002 Avalanche that I bought in 04.  Was imported down from British Columbia, BC.  The auto climate control worked, but was in Celsius.  So I purchased another HVAC controller (used) that was in F˚.  Noticed about a year ago that the lower four buttons (air recirc, AC, defrost) don't have backlighting.  Most of the time during the day it's not an issue, but it makes it hard to select the right buttons at night.  So I found another used controller on eBay.  Got it and swapped it out and the lower buttons still don't light up.

Is there a fuse that is blown or do I have bad luck and have purchased two bad units in a row?

Suggestions?  I'd rather not resort to pulling the units apart as I'm not a solder kind of guy...just don't know how.

I think they are small LED's soldered to the board.... I know you said you were against this, but can the controller be easily opened just to verify?

That happened to my '03 as well.  I'm not afraid of solder, but I recall looking at the procedure somewhere and it seemed a pain to take the thing apart-- so I just left mine alone.  And this is coming from someone who has taken out the instrument cluster to unsolder and replace the needle stepper motors (all 6 or 8 of them, can't remember) and also soldered to fix dimly lit PRND321 lights...  I was successful at the instrument cluster.  I guess it just didn't piss me off bad enough to disassemble the hvac control module.  However--  if you have 2 of them, you might not need to buy any additional led's and just replace the bad ones with good ones from the spare.  If you do this, definitely look for burnt surface mount resistors (easily seen by brown circuit board areas)... this was a gm issue in the instrument cluster and probably also in the hvac controller. 

It's been years since I've had one apart but IIRC, they're not that terrible to do. You have a spare, experiment with it.

Found a company online who rebuilds the climate control units.  Will even give you a discount if you send in your old unit.  Tanin Auto Electronix.  Just got my new one and will install tomorrow.

triaker said:

Found a company online who rebuilds the climate control units.  Will even give you a discount if you send in your old unit.  Tanin Auto Electronix.  Just got my new one and will install tomorrow.

Click to expand...

Oh cool, good to know.  I need to get mine fixed, when it's cold outside the temperature goes down when I turn it up.