4x4 inop

I have a 97 Jimmy the front axle is not engaugeing. I checkek the vacume actuator the cable to the axle and everything but tear out the front diff. Everything but the front 2 axles is working properly. Anybody got any ideas?

Vacuum leak?

Checked all the vacuum hoses?

I had a similar issue. I disconnected the + battery cable for an hour or so to reset my computer and walla.

Try that first.