when i put my truck in 4 lo or 4 hi the light on the switch lights up but the truck doesnt go into either. the only time i can use my 4 wheel drive is if i leave it in auto 4 wheel...any suggestions would be greatly appreciated..thanks

Bambislayer40:

On a very quiet day, with the truck not running, push the 4wd button. You should faintly hear the solenoid (relay) on the transafer case pulling in. (very faint).

If you cannot, there is a good chance the solenoid has failed. (you would still get the light on the dash to read)

Had this problem on my 95 Suburban. Since then, the 99's we bought (for the company) have the old fashioned floor lever on the hump.

Its not that big a deal to change the soleniod, but definitely not fun in the driveway in the winter!

Good luck with it!

Mike in Subtropical Connecticut
(UP to 28 degrees!)

I don't know about the '99s, but my '96 has this problem. It was the actuator (in the front diff?). Evidently it was a design that had to heat up electrically before the actuator would engage. Was prone to going bad.

Last Friday night I was STUCK in a snowy / frozen driveway. I have a 98' GMC 4WD Suburban. The outside temp was -9 f. As I was trying to get myself unSTUCK I could not get my rig into 4HI or 4LO. I ended up with id STUCK in 4WD Neutral(?). I have never seen this before. I was able to get out the next day after backing up and getting a running start at the hill in the driveway. After reading the manual, I tried every thing it suggested in getting it out of 4WD Neutral. But nothing seemed to work. Until I remembered that the transfer case never seemed to make the winding sound it usually makes when turning off the truck.
So, I checked the FUSES and the 20amp Transfer fuse was blown. But, when trying to change the fuse with the engine NOT running, I blew two more fuses. So, I FINALLY tried replacing the fuse with the engine running and it jumped into 4HI and I was able to stitch it to 2WD and ALL IS GOOD.

<<<<ALWAY CHECK THE FUSES>>>>
Good luck,
BrightGuy