2005 GMC Sierra 1500 Interior Lights Sporatically Dim

jmpidgeo · February 27, 2013

Hello everyone,

I recently acquired a 2005 GMC Sierra with the L33 5.3, 4L60E automatic, and push button 4x4.

For whatever reason, the interior lights dim on and off randomly when driving down the road, at random times, but not all the time. Last night while fiddling, I THINK I have it narrowed down to the switch, because I could get it to act up as I was moving the switch side to side.

An example of the strange behavior: Dimmer switch set to full bright, interior lights dim all the way to off. I can bring the dimmer switch back down to low and the lights will come back. Sometimes dimming the switch brighter makes the lights dimmer, while this issue is occuring.

I was thinking on trying a junkyard switch just to see if that fixes the issue, but thought I would ask here first.

Thanks in advance for the help!

00Silverado4x4 · February 27, 2013

From your descriptions and based on my personal experience with a much older model ('76 Chevy pickup) I'd say that the switch sounds like it's failing. I've not heard of anyone having this problem with this model truck but you doesn't mean it hasn't happened either. I agree I'd try a junkyard switch for confirmation.

jmpidgeo · February 27, 2013

Sounds good, I'll be going to pick up a junkyard switch sometime tomorrow!

jmpidgeo · March 12, 2013

Went and picked up a J/Y switch, problem seems to be solved as of now. Didn't even realize that the lights in the swtich were out too, so thats a bonus.

Chris · March 12, 2013

Yes I ruled it to be a switch a while back in my truck, my subs, a bump, or rough road would make them dim. I pulled a friends switch and tried it for a night in my truck, it fixed it. I have been too cheap to buy one. I have an 04 with 113k and a lot of night driving. Since you got a junkyard switch, no telling how much life it has left in it

jmpidgeo · March 13, 2013

Yes I ruled it to be a switch a while back in my truck, my subs, a bump, or rough road would make them dim. I pulled a friends switch and tried it for a night in my truck, it fixed it. I have been too cheap to buy one. I have an 04 with 113k and a lot of night driving. Since you got a junkyard switch, no telling how much life it has left in it

yeah that is why I got 4 of them! 3 spares await the next requirement for one.

I'll send ya one for cheap if you still need one

Chris · March 13, 2013

What did you pay? My local truck salvage has a few for like $30. I'm not too worried about it. At night on long drives I dim it anyways

jmpidgeo · March 13, 2013

I paid $10. No big deal, just let me know if you decide you want one. Mine weren't just dimming but turning all the way off so I couldn't read the speedo or anything. It was super annoying.