Have a 1998 S10 4wd that indicates that it is working by the push button lights but it is not. Did some checking and discovered the vacuum lines had holes in them.

Also checked the 4wd actuator under the battery tray. It looked ok, but only has a cable connected to it- no vacuum line. There is a male opening on it that looks like it could be for a vacuum line, but I am unsure.

Does anyone know if the 4wd actuator should have a vacuum line connected to it or only a cable?

 

It should have a vacuum line attached to it and a cable running down to the differential.

 

The vacuum hose that goes to the actuator comes over the engine and is a pretty large diameter hose. About 3/8 to 9/16in in diameter

 

Thanks, found it! 4WD now working!