RV Repair: electric solenoid on LP tank line, electric solenoid, hot water heater

Question
I have acquired a 95 Gulfstream Scenic Cruiser, Class A on a spartan chassis. The LP tank has an electric solenoid valve, normally closed, that supplies LP to the hot water heater, stove and fridge. When the chassis and coach power is on, the valve does not have power applied to open. I can not find a separate switch for it and it is not listed on the BCC schematic.. I am able to open the valve and use the appliances if I jump 12v to the solenoid from a power source. Any idea where it gets it's power from?? It's fed with a yellow and purple wire and I am unable to follow it's path to the power source..

Answer
Hi Al, A vast majority of the time they are hooked up to the LP detector. Turn on the detector and the valve opens. The thinking behind that is if the LP detector go's off, the LP flow is cut off. If that dose not work the ck for a blow fuse. If nothing else. You can eliminate it altogether. Good Luck.