How can I tell if my AWD works?

I just replaced the encoder(actuator motor) on the transfer case. I drove up the driveway(it’s gravel)and punched the throttle. Only the rear wheels spun. Last week when we had snow I didn’t have AWD so I took the vehicle to the local shop and paid $90 for a computer read out to find out I had an electrical short possibly caused by the encoder.

I think you know the answer already, your AWD isn’t working. Loose gravel is a good test and since just the rear wheels spun out, your AWD was not engaged.

Place a floor jack under the rear differential and raise the rear tires off the ground. Now place the transmission in gear and see if the vehicle moves while idling.


It could be that the back wheels spun, but the front wheels still had traction and kept the van moving forward.

Is that really a good idea? Most of the floor jacks I’ve had over the years don’t roll well enough (especially under load) for this to seem safe.

Well? You need a good quality floor jack that rolls under a load, you don’t raise the rear tires 6" off the floor, and you just crawl in gear while idling with your foot ready on the brake.


Before you went through the trouble of replacing the actuator motor, perhaps you should check and see if the wire that feeds the “encoder” is supplying the 12 volts needed to make it work…The problem could be at the other end of the wire or the wire itself…You could “hot-wire” the encoder and see if it engages the front axle…

I tried to jacking it up and no front wheel drive. I’ll try the hot wiring it but I goot to tell you before I replaced the encoder I did check the power goig down to it and found both the red and black wires to be hot going into the encoder. So I just figured the encoder had a short in it which I did a continuity test on and it showed a short. I will try hot wiring it next. Thanks

Only ONE wire should be “hot”…The other should be a ground. If BOTH are hot, then the ground wire is not connected or broken, which would explain your problem…The next thing you spend money on should be a service manual with a wiring diagram…