my 4wd light doesn't turn on when I go into 4wd any ideas. I've tried it in 4 low and still nothing.

 

Check your vacuum hoses on the front axle. Most of the time the four wheel drive light does not come on because the four wheel drive is not engaging.

 

should I take the truck to a shop to be looked at? I know the 4wd still works, I tried it on an icy corner.

 

Its probably the bulb then. Kurt

 

If you are sure it is engaging, it could be the bulb, switch, or wiring from the switch.

 

I have the same problem. My 4WD engages for sure but the light would only come on in a hard right turn (found that out whilst changing the rear diff fluid and figure eighting around). The lights are LEDs I believe and most likely will not wear out (seeing as how it is one of the least used bulbs). I think it must be a vacuum problem or electrical connection. Either that or I just keep turning right....

 

Are they really led's? I thought I saw a bunch of little twist plugs on the back of my cluster when I had it out. I agree that it could be the switch or something else as a lot can get hung up under there. I guess if it is actually going into 4x4 I'd start at the disconnect and trace the wiring into the cab. Again, this is a good project for the multimeter. Kurt

 

Not LED's. Definitley twist plug. Easy to check. Pry off bezel, unscrew instrument panel, (4 phillips screws), pull out panel. Look on the back for the 4X4. My cruise bulb was out and I don't have 4 x 4 so I swapped that bulb over.

 

Sorry about that. I haven't checked my bulbs yet, but my manual says that the EMIC controls all the lights and only some of them are incandesant. The rest are hardwired to the panel LEDs.

"An amber
lens behind the cutout in the opaque layer of the
overlay causes the “4WD” text to appear in amber
through the translucent outer layer of the overlay
when the indicator is illuminated from behind by a
Light Emitting Diode (LED) soldered onto the instrument
cluster electronic circuit board. The four-wheel
drive indicator is serviced as a unit with the instrument
cluster."

Maybe all the instrument clusters are the same....

 

cant help yea because at random intervals my 4wd light comes on and i have a 2wd truck

 

You have just entered....

The twilight zone

 

I had the same issue on my truck ('98 12 valve 4X4). I disconnected the wiring harness from the switch on the front CAD actuator, removed the switch, cleaned it with brake cleaner, reinstalled switch, and reconnected switch. Never had the problem again in six years. Go figure.