4wd Engaged light comes on during long drive?

[sled_dog]

Alright if I drive my burb for a long time at a constant fast speed the 4wd engaged light on the dash comes on. Its bothers me cause all I can do is smack the shifter to make sure its really in 2HI and hope the tcase isn't somehow engaged. This is a 241 Tcase behind an SM465. Last time it happened ot me was when I moved out here to Blairsville, I drove the turnpike the whole way doing 65MPH. It came on dimly at first, then full on bright, then dimly went out and cycled like that for a time. Today it just came on dimly enough you could read the words but not like it does when it is really in 4 wheel. I almost think the fluid gets hot and somehow sets off the switch but that about doesn't make sense. The light works fine when I put it in 4 hi or lo. Any thoughts? I haven't climbed under it and checked the wiring because until yesterday my road and driveway were covered in slush.

 

[dyeager535]

Perhaps the shifter jiggles enough to make contact? Does it go off if you shift the t-case into 4 then back to 2?

 

[tRustyK5]

I don't think it has anything to do with the T-case, I think it could be a ground problem. Of all things, my truck does the same thing, except there isn't a single wire hooked up to my SM 465 or 205 shifter. I didn't even know my truck had a 4x4 engaged light until it came on (dimly at first) about a week ago.

I have some other dash cluster problems, which makes me suspect a poor ground though. I have no dash lights, and the fuel gauge is pegged as 'full' as the needle will go.

I'm thinking the 4x4 engaged light is a ground interupt circuit like the dome lights. There is constant power to the light, but ground is only provided when the shifter ground a switch. In my case it must be robbing ground from somewhere else.

Does everything else work on the guage cluster on your 'Burb?

Rene

 

[sled_dog]

yeah my dome light is on all the time now so I have ground issues there. It blinks on and off and if I kick the kick panel it goes off, sometimes.

 

[chrisb420]

4wd coming on

i had a problem like this in 2000 on my zr2 blazer after driving for awhile i would see the light come on it was still under warranty at the time and the chevy dealer found an open wire that was grounding against the engine block.