When we used tow dolly I .had spare in bay under the coach. I also carried a small floor jack and 4 way tire iron. Never used the spare. Pulled out the floor jack to help a guy with flat on enclosed trailer. His jack for his pickup was too tall. Also lug nuts on trailer were larger than pickup. Floor jack was gold in that case. 4 way as well. Both about 60.00 at Harbor Freight.
Had the same problem. Started checking and found the on-off switch next to the oil dipstick got bumped off when they serviced the genny. This is separate from the circuit breakers. 2008 8000 QD. It is in a stupid place. There so you can fire up genny during motor service work and not be feeding juice to unknown places. Look close and hope this is it.