The running lights on our 5th wheel now come on and will not shut off whenever we hook it up to AC or have a charge on the battery. We have had it parked for a month now and the problem just started. Any suggestions?
There may be an explanation to the running lights lighting due to an electrical malfunction, but another possibility should also be considered.
You did not mention if you acquired your fifth wheel new or used. If you got it new, then it's likely solely a malfunction. However if it was used, the previous owner could have inserted a switch to light the running lights when the coach is parked. This practice seems to be popular is some locales.
My first thought was, if your coach was owned by someone else you may have inadvertently tripped that switch.
Failing that, I would check the wiring harness that connects the fifth wheel to your tow vehicle for a possible connection being made that would cause the lights to go on.
Electrical troubleshooting is done by working backwards in a circuit from the lights to the plug to the tow vehicle, and testing all the way, isolating circuits until the closed circuit is found.
Do you have a multitester for your troubleshooting? not just a voltage tester, but a multitester to also test continuity?
If the running lights are coming on and staying on the first place I'd look is the power connector that hooks to your tow vehicle's light system. On this connector there will be a "notch" or "Key" way, the battery is on one side of the notch, running lights on the other, It is possible that some stray wires have gotten toghether inside the plug and shorted these two leads together.
Second is the cord said plug is on the end of I suspect either the plug or the cord OUTSIDE the rig.
Problems inside the rig are also possible, however less so than outside