It seems that at least some of the new Class C’s do not have a BIRD or BCC to recharge the chassis battery from the engine alternator, so it is not surprising that a 2003 coach was built that way. The only issue I can see with using the emergency switch as a solenoid is heat. The emergency switch and wiring may not be designed for sustained use and could heat up and cause a fire. I would carefully check the emergency switch wiring gauge and check and see if the wiring or switch gets hot. If you have a generator, it probably would be safer (but not as convenient) to use the emergency switch to start the generator and charge the house batteries from there.
__________________
|