So I'm working on a buddy's truck and I'm working on the esof now. Just randomly stopped working. So trying to figure out why.

Dash switch has voltage and ohms tested right in all positions.

Relays aren't clicking when the **** is turned. 86 and 87 show 12v on both relays regardless of key on or off.

87a has a good ground.

Solenoid middle wire shows 12v with key on. But both outside wires show grounded regardless of switch positions.

If I jump from 86 to 30 it shows voltage to the switch motor. So there's not a break to the switch motor.

All the fuses under dash and under hood aren't blown. But did find that fuse 16 under the dash has no power.

The hubs are in manual lock mode and the 4x4 light only illuminates for a brief second as you start the vehicle. They do not turn on with just the key turned to on.

Any ideas I'm open.

 

Sounds like the GEM is not commanding the relays. Did you check the connections from the switch to the GEM? Also - the GEM likes to get wet if the windshield leaks - any water on the passenger-side floor?

One thing - the switch uses resistance to command the GEM. I think there's two different resistors in it - one for 4x4HIGH and one for 4x4LOW.

 

I need to get the pinout charts and then I'll do some more wire hunting. I'm leaning towards the gem being bad but want to make sure before spending money on one.

I checked the resistance on the switch in all three positions. I forget the numbers but they were all within the acceptable range.