New Guy From Kansas

jtkustomizer · December 10, 2008

I am new to this forum and I am having problems with the 4wheel drive in my 1998 GMC Sierra Z71.

The truck is not going into 4wheel drive like it is supposed too. When I put the key in and turn the truck on the lights on the switch all turn on and then go off after about 5-10 seconds. I can push the 4wd hi button and the both lo and high lights go on and blink continually and the truck doesnt lock into 4wd. If I push the lo button itswitches into lo just fine and everything locks in like normal.

I took it to a dealership and they told me the switch in the dash was bad and that the actuator in the front differential was bad as well. My dad has the exact same truck and everything works just fine on it, so I switched the switch and actuator out of his and into mine and it still does the same stuff and his is works just like it is supposed to.

Here is some pics of my truck

Later

JT

DofD · December 10, 2008

Hi there and welcome to GM Trucks! Nice truck you've got there.

The switch and actuator going bad are pretty common. But since you've eliminated those, hmm. Have you checked the wiring between the switch and actuator? Other than that, the better experienced here will need to chime in.