Service 4wd

Discussion in 'Chevy Silverado Forum (GMC Sierra)' started by ol dude, Nov 5, 2013.

  1. ol dude

    ol dude New Member

    From my research, this topic seems beaten to death, but I'm wondering the usual troubleshooting steps. I may not even need to troubleshoot further and might have found the problem, but thought I'd ask some of you guys. My "Service 4wd" light has come on. At first glance it doesnt seem to want to switch out of 2wd. The 2wd light was illuminated, but then the lights along the 4wd panel all went off, so none of the lights were illuminated. However, this morning I decided to turn the truck on and immediately push the Auto 4wd button while it was still illuminated, pushed it pretty hard, and then the indicator light switched over to Auto 4wd. So, its in Auto 4wd. Pushed hard again to switch it back to 2wd, and the indicator light sure enough went to 2wd. Then the indicator lights went off. So I knew it was in 2wd, but a quick glance you wouldnt be able to tell with the indicator light being off. I was able to reproduce this by shutting the truck off. Upon restart, I quickly pressed the 4wd buttons hard and it would switch, but then after a few more seconds the indicator light would go off. So, my first thought is this 4wd switch panel is bad or shorting out somewhere. But, I'm not sure. Any thoughts or ideas of next steps to troubleshoot/check?

    1999 Silverado Z71
    265,000 miles
  2. dsfloyd

    dsfloyd Epic Member 5+ Years ROTM Winner 1000 Posts

    I know there were issues with the soldering on the switches so you might start there.
  3. ol dude

    ol dude New Member

    Thats what I'm thinking, since the lights are going on and off, and the buttons dont always want to work. It seems isolated to that panel, but was curious on any other ideas or if Im in the right direction.
  4. j cat

    j cat Epic Member 5+ Years 1000 Posts

    with your problem and the age just replace this switch . if this occurred like my 2000 with 30,000miles on it I would say get the soldering iron out if your up to that type of electrical work.

    I did the complete job in 45 min.. it just pops off.. new switch I think is 25-30 USD,,,
  5. ol dude

    ol dude New Member

    I took apart the dash again, took the 4wd switch panel out and the cover off so that you are looking at the system board. Theres a black rubber piece about 2.5-3 inches long that is used to trigger each setting when the buttons are depressed. Played with each 4wd setting by just pressing the rubber piece, and it worked flawlessly. So, the buttons and the plastic clear piece on the inside of the panel suck, basically. Replacing the switch panel this week.
  6. j cat

    j cat Epic Member 5+ Years 1000 Posts

    with your mileage not bad if the switch failed I stated before my switch crapped out at 30,000miles ! Jose did a very poor soldering job !
  7. dsfloyd

    dsfloyd Epic Member 5+ Years ROTM Winner 1000 Posts

    now that you mention it this way I had a similar problem where I couldnt get it back into 2wd because the button just seemed real hard and didnt do anything. I ended up having a small piece of plastic that broke on that one switch and was keeping it from depressing far enough. pulled out the broke piece of plastic and it worked perfectly fine.
  8. Guardrail

    Guardrail Member

    I had a 99 that did this. I screwed with the switch several times and then finally just replaced it.
  9. BurbanMan

    BurbanMan Rockstar 3 Years 500 Posts

    My wife's Tahoe will only go in to 4wd or back in to 2wd if it is in neutral. Is that normal or is that a switch problem?
  10. BRB46

    BRB46 Rockstar 100 Posts

    Not sure, but that sounds like more than just the switch. Do any or all of the indicator lights work as they should. If the switch were out I don't think it would work at all.

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