4WD Selector Switch Module - Opened up to see inside

Discussion in 'GM Electrical Tech' started by Springthing, Jan 3, 2009.

  1. Springthing

    Springthing Epic Member 5+ Years 1000 Posts

    Recently replaced the switch module (push-button 4wd) so I opened the old one to see how the inside looked. There was a post recently on changing out the lights on the gauge cluster and figured I'd see if it was possible and how easy or not it would be to do the same to items like the switch module. Seems like it would be easily done.

    So, just for your reference, here's what the inside looks like!

    (btw, the switch module is taken out of the dash by carefully using some flat-head screw drivers to push the side tabs in and prying out the module. One tab per side directly in the middle.)


    A little difficult to see, but there is a red LED for the neutral indicator, four LEDs for the switch selector indicators, and two bulbs to light the buttons up when the lights/dash lights are on.

  2. MrShorty

    MrShorty Epic Member 5+ Years 1000 Posts

    Can you see any indication why these switches seem so prone to trouble? From other research, it seems that the problem GM had with the wiper circuit board was due to the cold solder they used on the circuit cracking. I was just wondering if maybe these have a similar problem or what is up.
  3. Springthing

    Springthing Epic Member 5+ Years 1000 Posts

    Hmm... I didn't think to look that closely at it.

    My issue was something to do with the wires/plugs/incoming connections. I'll have to take a closer look to see if I can diagnose what was wrong.
  4. aboston

    aboston Member

    Has anyone ever changed the incandescents on one of these switches? Mine a re burned out, and I took my switch apart, but couldn't figure out how to replace them without breaking the board. It must be glued down to the plastic housing. The little bulbs sit in a small socket that is soldered to the board, and I can't figure out how to remove them without having access to the back of the board. Theyprobably would just pull right out, but I only have one switch and don't want to break it permanantly. A new switch is about $80 and I don't want to pay that because 2 lights are out!! (I am a DIY kinda guy anyway...)
  5. Project Reaper

    Project Reaper Rockstar 100 Posts

    this is out of the sarge?
  6. cjduckk

    cjduckk New Member


    Oddly enough, I stumbled on this thread looking for a pinout of the two connectors on this module. I was able to remove the two incandescent bulbs (they didn't appear to be in any sort of socket, it's a bipin bulb soldered directly to the board). It was a tremendous pain! Since the board is held in place not only by those two clips, but also by the pins for the connectors, I had to desolder the 12 pins of the two connectors to get the board out.

    Anyway, now that I've got the bulbs out, I'm at a loss for what to replace them with. The smallest bulb I have is a 1330, which is too large. My boss had the idea to replace them with a couple of 12V stable LEDs, which is what I will attempt to do this afternoon.

    So, if anyone has a pinout of the 8-pin connector for this module, I can determine which direction to plug the LED in.
  7. aboston

    aboston Member

    I wish I had that pinout diagram for you, but I don't. I think it is time for me to buy a FSM.

    Please keep us updated on your progress. I would like to see what you ended you using and what the end result was. A new switch is about $80, and that seems like a lot of cash to drop because of 2 dead lights!

    So you de-soldered the pins from the board also? Did they stay in the housing? I am wondering if the board is glued down then too, and also whether or not you think you will be able to get it back together again!

  8. Dan Faust

    Dan Faust New Member

    I'm at the same point with my 2003 Chevy Silverado HD. Incandescents are burnt out in th 4WD switch. Board seems to be most difficult to remove so I may have to solder to the topside only.

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