Hello HEF! I got a Cat305e2 mini-ex and the RH Thumbwheel stopped working entirely. Active code for voltage above normal 1658-3 seems to be the problem, checked all the relays and fuses they're ok, plugged and unplugged the connector, its got battery voltage to the connector (well I think at least...not sure which wire is supposed to supply voltages). Looking like that thumbwheel switch is likely bad but before dropping $ id like to verify that I was hoping someone could help out with wiring diagram of any diagnostic help for that code? CAT 305e2 s/n H5M11340 Thanks!
Attached the troubleshooting procedure for 1685-3. I'll send you an electrical schematic The replacement Part Number is 528-5705, and that is for a complete handle assembly Ref #1. The thumbwheel switch is not sold separately.