Help, I have a 2000 GMC Sonoma 4x4 that the transfer case is engaging the front drive shaft but nothing happens to the front wheels. The push button lights come on fine in lo and hi. I was told an actuator is bad?? Is that the problem. Where is it located ?...Are there 2 actuators?? Vacum and in the transfer case ??..A local shop said $50-100 to diagnose it and over $500 to fix it.
Ive priced out the actuators and they seem to be only $ 50-60. I can not afford to take it to a shop right now, but need the 4x4 working for the winter....HELP !!!

i have the same year of truck for my dd and have the same problem 4 wheel drive seems to work if i have momentum but as soon as i loose it its quits i dono what to tell you tho i know im gonna do a sas over thanksgiving hopefully

there is a vacuum switch on the transfer that sends vacuum to a servo under your battery.switch going bad is common.in the front end there is a washer that breaks dropping down that won't allow the gear to slide.your dealer should have the parts in stock its also very common.

Also when mine was stock I had a problem of the bearing wearing out on the front drive shaft where it connects to the tranfercase it would act like it wanted to engage but never would.

Help, I have a 2000 GMC Sonoma 4x4 that the transfer case is engaging the front drive shaft but nothing happens to the front wheels. The push button lights come on fine in lo and hi. I was told an actuator is bad?? Is that the problem. Where is it located ?...Are there 2 actuators?? Vacum and in the transfer case ??..A local shop said $50-100 to diagnose it and over $500 to fix it.
Ive priced out the actuators and they seem to be only $ 50-60. I can not afford to take it to a shop right now, but need the 4x4 working for the winter....HELP !!!

I can't remember what version yours has--but there are only 2 and thats in the vacuum switch.

You have a vacuum actuator under the battery(remove the battery and tray and you will see it).

Now either you have a vacuum switch on the t-case or the firewall. But put it into 4x4 and check for vacuum at the actuator. if there is none then follow vacuum hoses. One big problem we have is the vacuum switch on the t-case will get stuck...