[rohrmann]

Besides checking that your batteries are healthy, you should turn everything off, by disconnecting your shore cable, so you have no AC power coming into the rig. Then, at the electric panel, which has 120 volts AC in addition to 12 volts DC, tighten every screw that makes a wire connection on both the AC and DC sides of the panel. You should also check and tighten all the connections you can get to where the batteries are located. You will be surprised how many loose connections you will find, and hopefully this will solve your problems. You really don't need to disconnect from your batteries, but if you have a battery disconnect switch, you can turn that to remove 12 volts DC from your panel. At the battery location, be very careful when using a small wrench, that you may want to wrap with electrical tape so you don't accidentally short out to the frame while tightening connections.