Bought the truck used last Feb, noticed that 4wd indicator light did not work. Dealer looked at it, said switch was bad and agreed to ship me the part, included in the sale. I got it and put it under the back seat of the truck, and just never put it in. So today there's a lot of activity in the 4wd indicator light doesn't work thread, so I decide I'll got put the switch in and see if it fixes the issue. The switch is a two wire switch with a weatherpak connector. Before replacing the switch, I did the bulb test by holding the reset switch and turning the key on, the light worked.
The part number for the switch is 05134375AA.
7/8 or 22mm combo wrench
Here's a pic of the new switch
Step 1, crawl under truck, lay with chest under trans crossmember, and look up between front driveshaft and transmission. You will see the switch on top of the transfercase. Here's what you'll see.
Step 2, use wrench to remove old switch, after wiping any debris away from it. I found the old switch was installed with no copper washer, "O" ring, or any type of seal, and is straight thread, not pipe. Interesting. Old and new.
Step 3, I decided that since it is a two wire switch, I'd put a little pipe dope on it as some form of seal. I then installed the new switch, plugged in the connector, crawled out from under the truck, and cleaned up my tools. Hopped in the truck, turned on the key, and put it in 4wd, here's the result. It works!
All said and done, it took about 15 minutes to replace the switch. I could have ohmed it out to see if it was good or bad before I swapped it, but since I had it, and don't have my meter here tonight, I figured I'd just swap it. I can post pics of how to check the switch if anyone is interested.