H/L & 4WD Switch-Dark,No See-um

[Ironhorse]

2005 Tahoe with the push button AWD/4WD switch and the four position head light switch......all dark at night, no visible illumination at all. Am guessing maybe the LED (?) lights are burnt out? Are the internal lights serviceable or must one replace the entire switch to have the lights functioning again? My guess is the later as it seems Nothing is serviceable when it comes to cars and trucks now days.

[hatzie]

You can replace the illumination lamps. They're around 4mm tungsten filament bulbs with blue silicone caps soldered to a circuit board or in a holder.
You can use LEDs but the light won't match the rest of the dash and door switch lamps. The tungsten bulbs typically last around 15 years so they'll outlast your ownership of the truck.

I did my headlamp switch. The dimmer got flaky a few months later so I replaced the switch. Didn't even think to look at the solder connections. The switch was pretty nasty so I didn't really want to keep it. The illumination bulb is mounted in a little 1/4 turn holder.
IIRC the switches were not expensive at all.

2003-2006 GMT800 Headlamp Switch Repair

The plastic on the 4x4 switch was super brittle and it cracked even tho I used guitar picks slid down along the sides between the inner and outer parts of the switch body to release the plastic from the projections rather than push the plastic wide with a spudger.
The bulbs and switches are mounted to a super thin printed circuit board inside.
The other problem is the 4x4 switch has high density .010 pin pitch connectors that are molded into the rear of the switch housing.
To replace the bulb you need to desolder the PC board from the connectors and once the bulbs are replaced you need to solder the board back to the connector pins. I would highly recommend that you use a vacuum desoldering station. The switch board is super thin and it doesn't dissipate heat as well as a standard thickness board and the density of the pins is such that it's difficult to get all the solder out of the holes with braid and/or the spring-loaded solder suckers. You'll end up with lifted and torn pads without the proper tools.

[Ironhorse]

Thanks for the reply. From reading your post not sure these old hands and eyes are up to that sort of delicate work. May just wind up buying new switches and going on from there. That sort of soldering such small wires and boards, not sure I want to attempt that. Sure is tough getting old but it beats the alternative.

[hatzie]

The headlamp switch is fairly easy. No soldering outside of possibly touching up cracked solder joints on the connector pins on the board. Look at Jeffs' video that I posted.

The 4x4 switch is fairly difficult to fix and I've done board repair like this. I did fix the switch that came out of my truck despite the cracked plastic so I could have a spare. I wouldn't attempt this one if you aren't supremely confident in your soldering and PC board rework skills.

[MJN]

There are a few places out there that will replace the bulbs with LED's for you such as https://carradiobulbs.com/store-4/03...grade-service/

[hatzie]

The 4x4 switches are so cheap it's not worth sending em out. I think I paid $35 for mine.
After you get done with shipping both directions and paying for the tech it'll cost more than that.

The only way it's worth fixing is if you can do the work yourself.

[MJN]

Originally Posted by hatzie

The 4x4 switches are so cheap it's not worth sending em out. I think I paid $35 for mine.
After you get done with shipping both directions and paying for the tech it'll cost more than that.

The only way it's worth fixing is if you can do the work yourself.

Just a suggestion for those wanting the option of having it fixed and LED's installed that cannot do it themselves.

[Ironhorse]

Thanks for the replies and info. I'm finding out more and more with the newer vehicles somewhere down the line I got left behind in the tech department. I pretty much cut my teeth playing with carbs, points and condensers, changing plugs every 10,000, oil every 2 or 3 thousand miles. These newer vehicles sure aren't very user friendly to that type of background at all. Pretty sure will be visiting with my local trusted mechanic shop for a fix.

[hatzie]

Originally Posted by Ironhorse

Thanks for the replies and info. I'm finding out more and more with the newer vehicles somewhere down the line I got left behind in the tech department. I pretty much cut my teeth playing with carbs, points and condensers, changing plugs every 10,000, oil every 2 or 3 thousand miles. These newer vehicles sure aren't very user friendly to that type of background at all. Pretty sure will be visiting with my local trusted mechanic shop for a fix.

I'm an old fart too. I come from the same background. My first car was a 1972 Pontiac Bonneville Wagon 455, Rochester 2G, and points ignition. My 1977 Rabbit was CIS fuel injection with a plethora of relays and breaker points ignition. I moved from that to Bosch VE Diesel Fuel Injection on several 70's and 80's machines.

Don't be frightened of the new machines. Nothing ooogie booogie about the electronics.
Soldering circuit boards is a rarely needed talent.
You can find videos about troubleshooting and most maintenance and repair operations. Lots of good folks here too.