[Aaron K.]

I've been steady fixing little things here and there on my 89 W100. Next is the 4x4 engaged light on the dash next to the message center. The 4WD in the truck works fine, but the light doesnt at all, not in 4WD High or Low.

I checked the bulb and its good. I tried checking the two wires that go into the lights harness with a test light. I got the blue with white stripped wire to light up as a power source, thats with 4WD engaged or not. I couldnt get the green with red stripped wire to light the test light testing it as a power source or ground with the 4WD both engaged or disengaged.

I got under the truck to see what I could see in that area and found this dangling wire:

Where does this connect and could this be why my stupid little light doesnt work ?

 

[Dakotah18]

it kinda looks like a wire connector i found on the back of my cig lighter plug on my '93 Dak. I'm not sure what yours goes to. I've heard alot of these lights fail because the switch on the tcase gets worn out

 

[NEEDNODEPENDENT]

on my 93 the switch is on the front diff (d44) where the vacuum operated engagement is it quit working due to a squirrel eating the wire into

 

[Chump]

See if this helps...

 

[andy2]

plug it in, see what it does. i think that switch is still available in aftermarket. also, get a cheap test light and trace the power in the wire all the way to the switch on the diff.

 

[zerko]

Hey there

Did you get any results yet? The sensor on the fron CAD usually goes bad- mine still is!
Pull it out, and check for continuity. It should make contact ( ground ) when ball is fully out, and break contact when pushed in. Only negative "power" runs through these wires, the positive power to the indicator light comes from #12 fuse ( 5 amp ). If the colors are correct, the light green/brown goes to the light, and the other goes to a grounding point in the dash.

Also, the lone wire you have found? Is your truck standard? If so, do your reverse lights work? I have conflicting info, but some have a single wire or 2 wires for reverse.
It might go on the other side.

Good luck.

 

[Aaron K.]

Hey there

Did you get any results yet? The sensor on the fron CAD usually goes bad- mine still is!
Pull it out, and check for continuity. It should make contact ( ground ) when ball is fully out, and break contact when pushed in. Only negative "power" runs through these wires, the positive power to the indicator light comes from #12 fuse ( 5 amp ). If the colors are correct, the light green/brown goes to the light, and the other goes to a grounding point in the dash.

Also, the lone wire you have found? Is your truck standard? If so, do your reverse lights work? I have conflicting info, but some have a single wire or 2 wires for reverse.
It might go on the other side.

Good luck.

No, I havent messed with it since I kinda forgot about it, lol. I have a long weekend coming up, so I'll check it out then and report back.

Oh, and the truck is an auto and my reverse lights currently work.

 

[zerko]

Sorry, when I saw the silicone and what I thought was a "starter bulge", it looked like the standard tranny picture. I now know that you have the A727 tranny, because that's what was used in the older 4x4 ( yours is a 3 speed, right?). If so, then that wire is most likely to be for the "part throttle unlock relay". My book says that it is a dark blue wire. The A727 is a NON-lockup tranny, and that wire is not used on your truck. I want to go and look at mine ( same truck!), but, it's too damn cold right now!

Anyhow, hopefully this will solve "something" for you when you get time to fix-er!

 

[Aaron K.]

I got under there earlier today just to look around to see what I could see. I pulled the connector off and the contacts looked dirty and corroded. I didnt have time to test anything, so maybe I'll get to that tomorrow.