Nasty, Nasty Electrical Issue
A friend asked me to look at his trailer. None of the 12 volt systems were working and the battery wouldn't take a charge.
The first issue was easy. The battery was toast. Installed a new deep cycle battery but when I connected the cable there was a large spark. No, I didn't hook them up backwards. I connected shore power and there still was no life in the 12 volt system. The converter and reverse polarity fuses were both popped. New fuses blew right away. I disconnected the converter 12 volt side and the fuses didn't blow but I still had no power on the 12 volt side. Located the junction box at the front of the trailer that had the self resetting breaker. Of course it was covered by the hard plastic belly pan. The breaker was tripped and trying to temporarily jump it resulted in some spectacular fireworks. So somewhere between the front of the trailer and the back, there was a dead short to ground in the main power feed.
There is a full hard plastic belly pan from front to back so tracing the harness was going to be a pain. While I was dropping it down, I thought I could see a small section of convaluted tubing pinched between the wood structure and the trailer frame above the RR tire. Upon further inspection I found that when they built the trailer 5 years previously, they pinched the harness between the wall framing and the main trailer frame. The problem with fixing it, other than the belly pan was that the black water tank was on the inside of the frame right at this point. So even after dropping the belly pan, I would have to drop the black water tank to access the wiring. Nope, I wasn't going there.
I managed to cut out a 6" section of the bottom wood frame right where the wire was pinched. There was enough slack in the wire to cut out the bad section and do a proper crimp, solder and heat shrink slice. I fitted a new piece of 2x2 and glued it in place with the harness pushed into its proper place.
Everything was now working, sort of. The 30 amp breaker at the front had seen too much of a hard life and was now tripping at around 6 amps. A new 30 amp breaker fixed that. All I had to do was reassemble the belly pan and seal everything up.
The first issue was easy. The battery was toast. Installed a new deep cycle battery but when I connected the cable there was a large spark. No, I didn't hook them up backwards. I connected shore power and there still was no life in the 12 volt system. The converter and reverse polarity fuses were both popped. New fuses blew right away. I disconnected the converter 12 volt side and the fuses didn't blow but I still had no power on the 12 volt side. Located the junction box at the front of the trailer that had the self resetting breaker. Of course it was covered by the hard plastic belly pan. The breaker was tripped and trying to temporarily jump it resulted in some spectacular fireworks. So somewhere between the front of the trailer and the back, there was a dead short to ground in the main power feed.
There is a full hard plastic belly pan from front to back so tracing the harness was going to be a pain. While I was dropping it down, I thought I could see a small section of convaluted tubing pinched between the wood structure and the trailer frame above the RR tire. Upon further inspection I found that when they built the trailer 5 years previously, they pinched the harness between the wall framing and the main trailer frame. The problem with fixing it, other than the belly pan was that the black water tank was on the inside of the frame right at this point. So even after dropping the belly pan, I would have to drop the black water tank to access the wiring. Nope, I wasn't going there.
I managed to cut out a 6" section of the bottom wood frame right where the wire was pinched. There was enough slack in the wire to cut out the bad section and do a proper crimp, solder and heat shrink slice. I fitted a new piece of 2x2 and glued it in place with the harness pushed into its proper place.
Everything was now working, sort of. The 30 amp breaker at the front had seen too much of a hard life and was now tripping at around 6 amps. A new 30 amp breaker fixed that. All I had to do was reassemble the belly pan and seal everything up.
