2005 GMC Sierra interior backlighting issues

[jlamb18]

I had quite a few bulbs out in my HVAC controller so I decided to swap them out with some new LED's. It first went perfectly until they all started going out one by one. I took a look and I realized I used the wrong resistors . I replaced all of the LED and resistors with the correct size and when I plugged it back in, only about 4 lights went on, and after a few seconds, smoke started pouring out the back. I unplugged it and figured I must've shorted something out, even though I tripled checked for shorts. Examining the board, I can easily see the lines that were impacted because they are all charred up.

 

My question is, could there've been something other than a short in the LEDs that could've caused this to happen? I examined the board for 20 minutes after looking for a short and couldn't find one.

 

My second question, is there a specific fuse that controls the lights behind the HVAC controller? I checked the HVAC fuses and they were all good. All the other backlights inside the truck work. Could I've fried the part of the board the controls the backlighting in the HVAC?

 

I am a noob to this type of stuff and to this forum so any help would be appreciated. Thanks.

 

Edit* The HVAC LCD screen works fine as well if that means anything

[Coby7]

Looks so easy on YouTube, I assume you have the Auto HVAC. Lamp voltage has no circuit on the module, it is connected direct to the bulbs. So you must have shorted something out. You could have avoided all these problems by using 12 volt LEDs.

http://www.led-switch.com/12%20volt%20LED.htm

 

 

[jlamb18]

@Coby7 , Thanks for the response.

 

I know using 12 volt LEDs would've been much easier to begin with but I only had standard 3.4 v LEDs at the time.

 

I'm having 2 main issues, 1. When power is applied to the board (from a power suply), not all of the LED's are lighting up, and 2. There is no power being supplied to the board from the truck. Here are some pctures to help explain my issue.

 

1. https://postimg.org/image/828gewdan/

These are the only LED's that light up when I apply 12v to the same terminals that the truck does

 

https://postimg.org/image/axljlrhan/

These are the next group of lights that light up when power is applied directly to anyone of them

 

https://postimg.org/image/cdx23wk7j/

These are the final group of lights.

 

They all work and light up, and I even did a continuity test on all of the positive terminals of the LED's to the positive supply terminal and they all registered. I'm not sure what would block the current unless the board is damaged.

 

2. https://postimg.org/image/xjquyhv0v/

Here's a picture of the board plugged into the truck. As you can see none of the lights come on, not even the first group a seen above. The dimmer switch is all the way up and the LCD screen works.

 

Any other advice on these issues would be great! Thanks

[Coby7]

I don't know of any advice, but seeing those pictures hurts.

[jlamb18]

Yup, something's always gotta go wrong. Thanks anyway.

 

I checked again for shorts and couldn't find anything. Looking at the board I think the lines are damaged from the short.

I ran jumper wires from the different "groupings" of LEDs (like so https://postimg.org/image/ww4zc9f7z/)and I plugged it into my power supply and all of the lights came on.

 

After fixing this problem I plugged it back into my truck, no light and more smoke. I'm still not sure what is causing the smoke or where it is coming from. I tried running a wire from the wiring connector in the truck itself directly to the positive terminal where the LEDs connect to in the HVAC controller. Still no luck.

 

Do you or anyone else know if that 12v wire that controls the LED's goes through a fuse I could've blown? If not, would pulling the stock 12v wire out of the LED source and replacing it with a secondary wire directly from the light dimmer itself work? Or is it not a good idea to mess with that type of stuff?

 

Again I'm still very new to this so any help would be great.

 

Thanks