Well, if it is a simple fused connection then it could just be the fuse is blown (sorry can't help find it, but if it is not in the builders fuse panels it might be an in line fuse buried somewhere).
As I noted previously, if the LP gas in your coach is controlled by an electric valve, the 12vdc voltage to the valve on/off switches may not get connected until the propane gas detector lockout relay is operated(if equipped with one). The propane detector in your coach "may" control the lockout relay. So if the propane detector is on (working) and not in alarm, it would operate the lockout relay, which would connect the 12vdc to your LP valve on/off switches. But I am only guessing here.....in lieu of someone else who knows your coach LP system coming on the Forum and saying the fuse is "here".
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