Charred wiring

[Rsc373]

Hello everyone. Our camper neighbors had an issue last night. I don’t know the model but it’s a 2016 Montana High Country. They went in for the night and went to turn on the furnace and no power to the thermostat, they have dual thermostats, one in the living room controls the main AC and furnace. A second thermostat in the bedroom controls the bedroom AC. Checked the fuse, no problems. We switched the thermostats (same models) still no power in the living room. So I opened the circuit/fuse box, the wire was charred/burnt. So we trimmed off about an inch of the wire and hooked it up everything worked. So the question is what caused the charring and should they be worried about a larger fire in the future?

[mlh]

Was it charred just on the end? If so I would suspect a bad connection.
Will it happen again? If this is the problem and it wasn’t fixed, yes it could happen again. Make sure the connection is clean and tight.
Lynwood

[PNW Fireguy]

Generally speaking it is heat. So what causes heat? Too much current, loose wiring, damaged insulation are the most prevelant three causes that come to mind.


After the field repair I would check with a clamp on ammeter to monitor over a day or two.

[rohrmann]

One of the best preventive maintenance projects to do is with the rig powered down, 12 volts OK to remain energized, check and tighten every connection in the electric panel and in the battery area, including all the connections to the hydraulic pump and anything else that you can find that has screw connections. Almost every connection I checked years ago was loose, almost to the point of getting hot. I'm not sure if they are afraid of over tightening these things, but they didn't put in much effort with a screwdriver.

[BB_TX]

Like Bob I checked all my connections shortly after we bought it. Probably half the wire connections were not properly tightened. And loose connections and bad crimps and worn outlets among others do cause overheating.

[Rsc373]

About a 1/2” of insulation was damaged, blackened and the exposed wire was black.

Also, they set the temperature pretty high, so I’m sure it runs a lot. I advised them to maybe set it lower so it wouldn’t run as often.

[WeBeFulltime]

Originally Posted by rohrmann

One of the best preventive maintenance projects to do is with the rig powered down, 12 volts OK to remain energized, check and tighten every connection in the electric panel and in the battery area, including all the connections to the hydraulic pump and anything else that you can find that has screw connections. Almost every connection I checked years ago was loose, almost to the point of getting hot. I'm not sure if they are afraid of over tightening these things, but they didn't put in much effort with a screwdriver.

Same here on 3 different new Montanas. As long as you're at it also check tightness of all the ground cables that are grounded to the frame in the battery compartment. I have found them not properly tightened sometimes.

[Ram Montana High Country]

I had to redo ground to frame connection on last trip - cable or bolt had no connection to frame.

[Our3231CK]

Is there a standard torque setting which should should be applied to all the electric connections? or has hand tight?

[BB_TX]

The screws on mine are standard Phillips head with a few slotted head. Not really something you worry about torqueing. Just good and tight, without over tightening to the point of risking twisting off the screw.

Should be done on all connections on both the 120 vac breaker panel and the 12 volt fuse panel.