Great news - I popped off the dash and found the cable wasn't connected to the switch! :rofl:
Plugged it in and bam they're working. Very very sticky and take a long time to engage and disengage, but eventually they work. I'll need to exercise them some more. :deadhorse:
Diff switch not...
OK, thanks. Yes, I'm in 4 Low, and CDL engages fine.
With engine off no sound under the truck when someone turns the switch.
I'll check the fuses and maybe the harness behind the dash too.
I have a '93 80 series, Japanese export. Doesn't do much offroading and so just today I tried enabling the RR/FF-RR switch and I'm not getting the blinking/solid red lights I was expecting. Also no noise or sounds as if it's attempting to engage.
I checked under the hood and axle code is K294...