4x4 problems/questions

i have a 1988 chevy 2500 4x4 with a 5.7 liter tbi motor, the problem is that the 4 wheel drive is not engaging, i was wondering what it could be, someone told me the actuator would be the problem but before i spend 90 bucks, i what to know what else i could be?

i have a 1988 chevy 2500 4x4 with a 5.7 liter tbi motor, the problem is that the 4 wheel drive is not engaging, i was wondering what it could be, someone told me the actuator would be the problem but before i spend 90 bucks, i what to know what else i could be?

You will have to craw under there and have a look.
Is 4W shifting in good?
Is the front axle locking in?
Old style 2 wire actuator?
Check fuse to it.
Got juice and ground?
Have a look at the wiring plug in to it.

i have a 1988 chevy 2500 4x4 with a 5.7 liter tbi motor, the problem is that the 4 wheel drive is not engaging, i was wondering what it could be, someone told me the actuator would be the problem but before i spend 90 bucks, i what to know what else i could be?

I can almost guarntee that is your problem. AND unless it has changed you will have to buy a different wiring harness to make it work which has one wire that runs ALLLLLL the way to the tailend of the tranny and must be "spliced in".

But it works like a charm when done. That's the good news.

He might not be able to use the updated actuator on his truck, the tsb excludes 1988 to 1993 that have a gvw over 8500lbs, and if he has 8 lug wheels the newer style actuator won't work

He might not be able to use the updated actuator on his truck, the tsb excludes 1988 to 1993 that have a gvw over 8500lbs, and if he has 8 lug wheels the newer style actuator won't work
My apologies. Good luck