My little Camo truck won't engage 4X4.

I'm thinking it's electrical. I checked all the fuses, they are good.

There is vacuum being developed, so that's not the problem.

I manually engaged the transfercase by removing a pin from the actuator linkage and that locked in the front driveshaft. I tried to do the same with the axle lock, but I couldn't muster the strength or get the timing of the spline right to get it to lock.

To engage 4X4, there is a push button on the 2 speed transfercase shift lever. I'm assuming that it does both the t-case and the front axle locking. The light on the dash doesn't light, as you would expect if nothing is happening.

How might I run this electrical gremlin down?

Lots of time to reply, I gotta hit the sack to get some shut-eye before nightshift.

Thanks in advance for any help offered