I wrote this months ago and forgot to post it….
If you don’t care about quality control in RV’s or how electrical wiring SHOULD be done, then maybe this isn’t a post for you.
I’ve owned a Forest River (FR) trailer. I’ve worked extensively on another FR trailer. I now own a FR class C. I’m working my way through my C making various upgrades and mods. The most common failure, by far, is the failure to properly crimp wires in butt connectors. Its not that hard to do correctly. Apparently it is very easy to do wrong.
This is the kind of connector, commonly used in RVs and certainly a favorite of FR factories. The proper way to make a connection with these is to strip your wire back 3/8ths to a half inch. Then put the two wires together and twist the strands tightly around each other. Then put the crimp on – and crimp with an appropriate crimp pliers.
Crimp pliers use a narrow surface so a lot of pressure is placed in a small area to tightly crimp the inner metal around the wire strands. If you use regular pliers, the pressure is spread and the crimp never really locks onto the strands. Yet I can see people in the factories using whatever tools that are handy. These two pictures show a crimp that was crimped with pliers (just flattened) and a pair of wires that weren’t twisted, nor crimped right and the crimp came off.
Here are some specific examples: Almost every connection I’ve had issues with – the wires were not twisted properly. It looks like the installer simply put the ends together – shove the crimp on and squeezed, but not hard enough. One sign of this is half the wire strands aren’t even inside the metal part of the crimp, having been shoved back as the crimp was pushed onto the wires. .
The brake break-away switch on my trailer was a fail. Three wires – 1. from the truck. 2 to the brakes 3 to the break away switch were half twisted, shoved into a crimp and crimped. But the switch wire in the half-ass twist attempt ended up wrapped around the insulation of the other two wires, not electrically connected to anything. Thus I had no NHTSA mandated safety switch was not connected.
On another trailer – the brake wire connection wasn’t fully crimped, nor twisted. When the wire was disturbed, the crimp actually fell off. The driver had been experienced intermittent issues with the trailer brakes.
I’m just getting started on my C. I explored under the bed box so I could extend power to the “other” side of the bed. There were three DC circuits passing through that were spliced (going from base to slide). There were 6 crimps. 3 of them fell off while handling. Fifty percent! One wire also had over half its strands not in the crimp.
A day later, I pull the board between the back of the stove and wall out (going to mount spice rack on it), and I look down behind. The stove has (had) nice lights built into the knobs that now don’t work. One wire came out of the crimp. Of course it had been crimped improperly.
So now I think – I have to examine EVERY connection on this vehicle! So far, I’m up to 6 bad circuits on a $100k vehicle. Many crimps are fine and were done with the proper tool. The area I haven’t fully explored is the main control panel. When installing my battery monitor, I needed to disconnect a wire 
from a switch so I could add in another small wire and the connector slipped off the wires. I expect most connections on that panel are also improperly crimped but I didn’t have time to go through and replace 25-30 crimps.
And there is also the notion that crimps are over-used. I replaced the radio and did some other work to the dash of the E450. This is what I found behind the knee panel under the steering wheel. All the power came off a single heavy wire. But there were multiple crimps after crimps and more crimps and inline fuses. So much was stuffed under there that the knee panel wouldn’t actually fit on properly.
I tried working with this mess but in the end, I cut it all out and solder spliced wires and ran circuits through a small 6 fuse box. Its much neater, and won’t burn my rig down when an unfused wire is shorted. None of these crimps were loose but they still were a mess. The wires are now all labeled as well so hopefully, the next person to touch them can actually know where they all go.
On my trailer – the main battery wire went from the battery 2 feet to the frame of the trailer where it connected to a circuit breaker. From the breaker it went 3 inches into an unsealed metal box. There I found a huge twist-on connector. The 8 gauge battery wire had been cut and the solar connector and both ends were in this massive twist-on connector. This isn’t allowed in AC circuits but not because of the high voltage, but because twist connectors on stranded wire IS A BAD THING! And this is a high current connection – one that is voltage drop sensitive.
Making electrical connection isn’t rocket science. Anyone on the line can be taught the correct method in just a few minutes. The tools aren’t very expensive. There simply is NO EXCUSE for sloppy work. These are problems that do not need to exist. They are an easy fix if only manufacturers cared about now screwing up or burning down our RVs.
This was one of the worst repairs we had to do on our Forest River Cedar Creek. We purchased brand new (we liked the new part but we learned the lesson too). They began using residential fridges in 2015 or so on these 5th wheels. We had lights flickering, the fridge turning off repeatedly, to the point we thought it was toast, jacks and slides breakers popping all the time, sensitive electronics were not powering correctly. It was a mess. We had a budget of $7,000 to figure out what to do to make this rig be ok when not plugged into 50amp. We went solar. Given the options it was the best case scenario for us. When we rewired the rig we found several things:
1. Batteries were wired incorrectly. We had 2 sets of batteries (4 total) and the 2 sets were not connected. The wiring diagram on our rig was not drawn properly. It took us 1.5 years and 6 RV mobile repairs, and 2 friends finally solved the puzzle on that one. We added the missing cables and Voila… power while not plugged in. This had caused issues with everything 12v on our rig at some point: slides, awnings, lights, jacks, and the fridge.
2. 1,000 watt modified sine inverters do not work with new residential refrigerators. It worked fine for years with the propane refrigerators but residential require more and more stable electricity.
3. Lights flickering after rewiring, still. The lights installed on our rig were UL tested and meant to be used for 12v systems. When we tested our rig and how much power was being sent to the lights- they were getting 14.75 intially and fluctuated down to 11.2v. We finally asked the manufacturer for new lights because we must have been getting the “bad batch” Forest River told everyone about. We have since been informed that the lights should not be getting that much energy and that the lights would operate fine on 12v but our 5th wheel produces too much power to each light, causing several of them to go dim and flicker, or even char. We were recently sent our third round of lights in 2 years, they said they are rated for higher (this remains to be tested).
4. Converter sent too much power to the batteries, overcharging them. We went through 6 RV batteries and our truck accessory battery before we discovered this one. Batteries were swelling and it took a little creativity tracing it back to the faulty converter.
The reason we pushed to figure out what we have was because we were seeing huge trends in our cedar creek forum where symptomatically, rigs between 2015-2017 were having these issues. When they began using residential fridges, they began putting 4 instead of 2 batteries on each rig, to help the massive power draw of the refrigerator. They failed to test the installment of moving from 2 batteries to 4. I’m really not sure how so many rigs “passed inspection” with such errors but there were so many buyers being effected by the same thing. In the past 2 years, John and I have learned more than we ever thought we would need to with a brand new RV. In a way that’s valuable because it’s handy to know on the road, but it does make us question if these rigs should have been allowed to be built in the first place.