I have a similar problem in my 2006 Beaver Monterey with a CAT C-9. The problem started a few days ago when driving in rain. When I activated my windshield wipers, they stopped in motion and then my ignition system stopped, all gauges to zero, ATC light lit on display. Ignition reset and was able to continue without wipers; thanks to Rain-X. A while later when in slow traffic and idling, ignition went off again and then reset; able to start and continue for 70 miles to campground. Next AM, I turned on wipers when in gear, wipers stopped in motion and engine shut down. Then able to drive to next stop, approximately 20 miles. Yesterday I moved a few miles and engine stopped five or six times when idling while stopped; reset and able to start again.
The windshield wipers are apparently a problem with Beaver, and I did see that there was a recall to replace the circuit breaker with a 15A.
I am in the CO rains now and wonder whether the rain could affect the switches. Replacement of the solenoid is a viable and easy option. Any input would be helpful.