I'm having Vu-ja-De...
YC1 helped me not too long ago with a similar issue with that solenoid! We have a 2002 HR 40' (Monaco) We ended up bypassing it altogether, so now only the Master Switch controls the 12v on/off. Might fix it later/Might not.
Our post/write up is here (with pics):
https://www.irv2.com/forums/f115/12v...er-634448.html
Hope it helps & have fun!
Kyle & Mercy