Electrical 12 volt problems

[humvee4me]

I'm RVing with our friends who just got into RV'ing and bought a Montana 5th wheel. They got it pretty loaded with generator, solar panels, inverter which is causing a problem. I am pretty experienced with RVing but haven't seen this problem before.

If they are connected to shore power all their appliances and lights work well; we are currently dry camping in Bishop for Mule Days. However, if they are just running on house battery about 1/2 of the lights won't work unless they turn on the generator, then all is well. So to run their fantastic fan they have to turn on the generator. I suspect it's a problem with the inverter, but need some expert advice to troubleshoot.

Their inverter is a Magnum ME-RC

Their rig is brand new and all under warranty, so they want to get things fixed properly, thanks in advance.

[DOUG2150]

I bet thats the converter instead . its job it to convert 110 into 12 volts the opposite ov an invertor hunt it down normally a box made of metal with a fan
if this is a new found problem maybe a way or a switch to change to all d c

[wa8yxm]

The key phrase in your post is this: The rig is brand new and under warranty.

Most lights in an RV are 12 volt, don't matter if incandasent, LED or Florescent they all run on 12vdc. In most modern under warranty rig there is no way 1/2 of the lights can work off battery and all of them on generator.. now in the old days this was possible.. One exception though.

If the working lights are in the "Cockpit' area.. Those may run off the chassis battery

Step one is to make sure your battery disconnect switch is not in the "Disconnected/Off/Store" condition.

Then visit the dealer

N ow if the non-workiung lights are 120 volt.. Well, that explains it, Unless they run off an inverter (I have one 120 volt lamp in this rig. it is a lamp though, not part of the rig)

[deandec]

The fantastic fan is likely 12v for sure. If it is not working, but other 12v lights work from battery power, then there must be more than one circuit for the various 12v power draws on the coach battery.

Separate circuits should mean a fuse panel somewhere where one fuse is blown and shutting down that circuit and at least one more fuse that is working.

[humvee4me]

Thanks all, my friend is taking it into the dealer when we get back home tomorrow, so we will find out soon what the problem is; thanks to all for the posts and the thoughts!!