Ok so the recent weather was finally a reason for me to kick the Silverado into 4x4.


This is the switch that my truck has-


The truck will go from 2Hi to 4Hi with no issue at all. It will not go into 4Lo. When you try and put it in 4Lo, the light will just blink.

Something is telling me actuator, but I'm not sure. Is this something a OB-Test would show? Anybody have any good guesses?

Are you shifting on the fly or from a stand-still?

I've tried it sitting still and going less than 10mpg (with the knowledge that the truck has to be moving for the transfer case to engage)

same result

I'm sorry if I sound nit-picky, just trying to help. When you put it in 4-lo at a stop, do you try going forward to see if it will eventually engage?

Oh no you're good (was just trying to show my limited knowledge)

Yeah I tried that... still doesn't go to 4Lo

OK, think of your electronic 4wd like a 4-wire/3-phase electric motor. You have Ground, and L-1, L-2, and L-3. (2-hi, 4-hi, 4-lo) It sounds like an electrical problem, like you've lost a "phase." It's not the ground since 4-hi still works. Unless any of our esteemed mech's on here have anything better, it sounds like a trip to a garage. Sorry, I wish I had more for you.

I was thinking either electrical like you said, the actuator at the transfer case or the switch has going bad (less likely)

Some vech require it to be in park or neutral to go to 4 low try that first

Well heck, you sir are the man.

Tried just what you said and it worked. Of course a smarter man than I would've figured that out by the "N" by the 4Lo setting.

Thanks bud

every one that I have owned does. I put mine in neutral. Some times I have to switch back and forth to get the light to quit blinking when I disengage. I like to switch in to 4lo once every month or so and engage locker just to keep everything working.

Yep neutral, then switch to 4Lo, then engage the transmission.

Gman

No problem glad it was a simple fix I work on them everyday and always learning something new. Good fishing