Electrical short

[Mwoods321]

Calling all electrical geniuses out there, I need your expertise please. I have a 2016 Cougar 333 MKS, during the off season a rat or mouse got into the rear of the trailer and crawled up the back wall and chewed some wires. Now when I plug in the shore power cord it kicks the breaker on the shore side. I also have no tail light or running light on the right rear side, and can see wire and wire sheathing remnants where the critters were at. Sounds bleak I know.
So I checked every fuse in the trailer to confirm they were good, and they were. Then I pulled out the 50 amp receptical from the trailer to check it for wiring issues, and it looks good. I crawled under the trailer and began removing the plastic sheeting that seals the underside so I could check the wiring. I checked the 50 amp cord and all the wires around it on the trailer from the rear bumper on the left side about half way through where the gas line begins near the axles, and all the wiring looks good. I pulled the right rear tail light off the trailer and checked the wires, and again they all look good. Ive checked and charged my batteries and the polarity etc, again looks good.
One question is if the running lights above the right rear tail light [which is out] are chewed some where, would that effect the tail light function, possibly grounding out,? and if so would that short cause the shore power breaker to trip? Last question, what am I missing or what else can I check? I do have an appt. At the dealer, but I know that exploratory surgery is going to be pricey, so I'm open, please help. Many thanks in advance.

[bobbecky]

The critters probably did chew through some wiring, and you just haven't found where yet. Your 50 amp shore cable in the trailer is 120 volts on two legs, and has nothing to do with the 12 volt stuff, although they could all be shorted together. If all you had was a problem on the 12 volt side, that can not cause a breaker to trip. And a problem in the 120 volt AC wiring can not cause a fuse to blow. Hope the repairs don't break the bank.

[Mwoods321]

Thank you.

[flybouy]

Unfortunately nothing short of visually inspecting the wiring will ensure a safe fix. Rodents (including squirrels) love to eat the insulation from wire and can do tremendous damage. Our daughter had a townhouse that she rented and it burned out, fortunately it was vacant at the time but the Fire Marshal said it was caused by mice eating the insulation from the electric water heater supply. Nothing to take lightly. Good luck, let us know how it turns out.

[Mwoods321]

I hadn't thought about a squirrel, but that makes sense, I can't find any urine or droppings you might see associated with mice or rats. Thank you for your input.

[14george]

Turn all your breakers off including the main breaker in trailerplug in turn main back on if it trips got to be the main wiring

[Pmedic4]

Originally Posted by Mwoods321

I hadn't thought about a squirrel, but that makes sense, I can't find any urine or droppings you might see associated with mice or rats. Thank you for your input.

Just bought our new 2017 fifthwheel a few months ago, and when we inspected it at the dealer there were some acorn shells all over it, when it was sitting in the dealers lot. I can't imagine mice carrying in anything like these acorns we found, so we suspected a squirrel too. No signs now, but sure made us wonder if we were going to be Julia Louis-Dreyfus character (Margo) in 'Christmas Vacation' some night.

Regarding your electrical short, I would say certainly some critter chewed through the main power line going to the inverter/fuse panel. Since you have the same model as we do, that wire runs quite a way from the rear of the RV to right in front of the entrance door, where the panel is located. I'm not certain of the route, yet if you saw some 'chewings', it's very likely right in that area. The power feed line is a rather large black, #6 - 4 wire cable, about 3/4" in diameter. When you do find the area, you could likely wrap some electrical tape around the exposed wiring to test if that is the only spot ruined, but seriously since this is a high amperage circuit (50 amps) on two wires I would have a professional electrician /RV Tech perform any permanent repair. They may even suggest replacement of the entire cable from the rear of the RV to the panel.

[JRTJH]

These are the only three pictures I can find from our time at the factory that show the 50 amp power cable in the "basement". It's the "thick black cable that runs along the coroplast, from the shore cable input to the converter/power center at the front of the trailer. It's not impossible to locate if you pull a few of the coroplast screws and use a flash light, but as said, for a permanent repair, make sure someone who knows what they're doing has the final word on whether it's a safe repair !!!!!

[Mwoods321]

Thank you. I did find the 50 amp cord and did pull that corollary. I was able to trace it from the rear bumper to the rear axle, then ran into the gas line. So far the 50 amp looks New and untouched. It didn't look like the critters made it inside the trailer and though I can see where they made entry, it seems they spent most of the time in the rear wall. It's frustrating, I'm guessing the shop will have to remove all of that colorplast and check everything. I don't mind getting my hands dirty so I'm trying to do some of the labor stuff myself. If I can find it, I'll have a pro check and repair it. Very frustrating.