Seems that it will engage into 4WD but the light doesn't come on. Any thoughts? How hard is it to get to the buld to check that?

 

Manual shift ? My 4wd light has been out on my dash for a while now. I really don't want to rip my dash apart.

 

Yeah it's a manual shift. I was reading that sometimes the sensor switch on top of the transfer case can get dirty or go bad. Might be what it is.

 

Several months back mine was also out. FWD worked great just no indicator light so I crawled under the truck and took the sending unit out and gave it the continuity check. Power was going in ok but not coming out which energizes the light on the dash. Called the local dealer and picked up a new sending unit {which is just a switch I was hoping I didn't have the light burned out in the dash what a chore that would be.
I have a 6 speed G-56 with the manual four wheel drive shift lever which when pulled into four wheel pushes on the ball on top of the switch which in return sends the voltage up to the dash light...

 

Try this. I did this and my 4WD light never came on which leads me to believe the light is burned out. I got this from another forum.

"1. Begin the test with the ignition switch in the OFF position.
2. Depress the odometer/trip odometer switch button.
3. While still holding the odometer/trip odometer switch button depressed, turn the ignition switch to the ON position, but do not start the engine.
4. Release the odometer/trip odometer switch button.
5. The instrument cluster will simultaneously begin to illuminate all of the operational segments in the LCD unit and perform a bulb check of each operational Light Emitting Diode (LED) indicator. The LCD segments and LED indicators remain illuminated as each gauge needle is swept to several calibration points and back. If a VFD segment or an LED indicator fails to illuminate, or if a gauge needle fails to sweep through the calibration points and back during this test, the instrument cluster must be replaced.
6. The self test is now completed. The instrument cluster will automatically exit the self-diagnostic mode and return to normal operation at the completion of the test. The self test will be aborted if the ignition switch is turned to the OFF position, or if a vehicle speed message indicating that the vehicle is moving is received from the PCM over the CAN data bus during the test. "

 

Excellent test forgot about that one. Then proceed to the fix..