Help Diagnosing Electrical Issue

As far as I can remember, you are the only one on the site who uses the term "main amp". Are you talking about the main 2-pole 50amp breaker in your power center OR the main 2-pole 50amp breaker in the campground power pedestal? I assume the former. It appears you are testing it to determine 0 volts on one side and 120 volts on the other. They can be replaced quite easily with the POWER TURNED OFF.


P.S. We've seen several instances of one side of the main campground pedestal breaker failing. It can happen to the one in your inside power center, too.
 
Mr. Dan said:
As far as I can remember, you are the only one on the site who uses the term "main amp". Are you talking about the main 2-pole 50amp breaker in your power center OR the main 2-pole 50amp breaker in the campground power pedestal? I assume the former.
Click to expand...

Thank you for the terminology correction, Mr. Dan. Obviously, I am not an electrician, but I have a healthy respect and fear of working it. :) Yes, it is the Main 2-Pole 50amp Breaker in the Power Center of the TT.

Can they just go bad? I am wondering if we just replace it or if I should be looking for an underlying cause of what shorted it out in the first place?
 
See the PM I sent

Salad said:
Thank you for the terminology correction, Mr. Dan. Obviously, I am not an electrician, but I have a healthy respect and fear of working it. :) Yes, it is the Main 2-Pole 50amp Breaker in the Power Center of the TT.

Can they just go bad? I am wondering if we just replace it or if I should be looking for an underlying cause of what shorted it out in the first place?
Click to expand...
See the PM I just sent you.

Measure the voltage between the terminal screw on the main (50 amp) breaker on the failed side and the neutral bus (where all the white wires connect).

If that is 0, the problem is NOT in the power center. It could be in the wiring between cord and the power center, the cord itself, or there might not be any power coming from the pedestal.

In a 50 amp RV, there are four wires in the cord: two hot (120 Vac) lines, a shared neutral, and ground. That's why the plug has four contacts. If one of the hot lines is open, you get the symptom you are seeing.

You can actually take your meter out to the pedestal, unplug the RV, and stick your meter leads into the outlet. The two parallel blades are the hot contacts. The third parallel blade is the shared neutral. (The round contact is ground.) Measure between ground and each of the parallel blades. Both should be 120 Vac. If one is not, the problem is in the pedestal. This is why I suggested you contact campground maintenance a day or two ago.
 
Larry-NC said:
See the PM I just sent you.

....
You can actually take your meter out to the pedestal, unplug the RV, and stick your meter leads into the outlet. The two parallel blades are the hot contacts. The third parallel blade is the shared neutral. (The round contact is ground.) Measure between ground and each of the parallel blades. Both should be 120 Vac. If one is not, the problem is in the pedestal. This is why I suggested you contact campground maintenance a day or two ago.
Click to expand...
I'm missing something. Where did you make this suggestion?
 
I had an issue where part of the trailer had no power. Traced to the male plug on the outside of the camper. Pulled the plug and the wires fell off.
 
Larry-NC said:
Measure the voltage between the terminal screw on the main (50 amp) breaker on the failed side and the neutral bus (where all the white wires connect).
Click to expand...
Main (50 amp) Breaker Right Side: 0 volts Left Side: 120 volts
We have ordered a new Main (50 amp) Breaker to replace.
 
Salad said:
Before taking our FR Vibe in for repairs that we could do ourselves I want to check with the forum to see if we are diagnosing our electric problem correctly and ask for help with the fix. We have used the camper several times with no prior issues.

We have a 2022 Forest River 32MS Vibe with solar panels

Electrical Issue started on an overnight stay on a return from a trip. At that stay, some of the power went out in the camper, could not find any blown breakers, surge protector at the post was fine. We continued on home with the limited power and have been trying to figure out what is causing the issue.

These are the steps we have taken so far…
When connected to Shore Power, these things do NOT work: Slides, Lights, Air Conditioner, and Thermostat.
Things that Do work: TV, Microwave, Outlets.
Battery is showing Full.
Tested the Converter (WFCO WF-9800) with voltmeter at 13.72

Called our RV Dealer to make an appointment, explained the situation, and was told that it sounded like a battery issue. So, we replaced the battery – but no change in situation.

Before ordering a new Converter, we ran a separate power cord to the Converter, rather than plugging it into the outlet on the back of the Distribution Center. Then, everything worked EXPECT the Air Conditioner will not kick on. Also, just the fan alone will not turn on. We can hear a couple clicks when we first turn the AC on, but that is it. (we have followed the reset instructions on the Air Conditioner by turning the Breaker off, waiting, and turning it back on.)

We tried plugging a small fan into the Outlet on the back of the Distribution Center (where the Converter plugs into), and it does not operate. So, we are thinking that it is a problem with the outlet. We replaced the Breaker, but the Distribution Center Outlet is still not working.

Does this sound like an issue with just the Outlet that can be fixed by replacing it? What steps are required to replace it?
Click to expand...

I would check your battery shut off switch. We had similar issues, replaced the switch and all worked. You can test that switch with a mulitmeter. We found a new switch at harbor Freight
 
Lanree said:
I would check your battery shut off switch. We had similar issues, replaced the switch and all worked. You can test that switch with a mulitmeter. We found a new switch at harbor Freight
Click to expand...

Doubtful. He is missing a 120VAC leg on the load side of the main breaker. We don't know about the line side of the breaker. That needs diagnosing and fixing before all else.
 
How to check the incomming power supply

Since you've been checking voltages, I'll assume you have a multi-meter that also has continuity (alert sound when probes are touched together) & resistance.


To check the main breaker, first remove the 50A plug from any power source. With the cover to the AC breaker center removed, set the meter on continuity and place one probe on one of the large wire (usually red or black) terminals and the other probe on one of the load breakers black wire terminal on the same side of the panel. The meter should sound. If not, operate the breaker several times (open-closed) and test again. Also test the other side of the breaker. The one you indicated as having power should sound right away. If no continuity, then the breaker is bad and can be replaced. They're readily available at places like Home Depot & Lowes, just take the old one with you to match it up. They're usually Square D brand but there's a couple of types available.


If the main is good, bring the power cable into the trailer and test from the plug end to the panel. The round pin is ground and should indicate continuity to the ground bus where all the bare copper conductors are terminated. The upper flat blade is neutral and should indicate continuity to the neutral bus where all the white wire are terminated. One of the flat blades (left or right) will be the red or black wire at the 50A breaker, the other will be the other side of the breaker. Also check on the resistance scale for close to 0 ohms, usually less than 0.5 ohms. If no continuity anywhere the plug connection to the trailer may be suspect, either the power cable or a wire connecting to the plug. Also take a look at the male prongs in the connector, if brown or tarnished, you have a high resistance connection and the plug / receptacle may be damaged. Remove the receptacle from the trailer and check for loose connections. Tighten all terminations.


I had a FR Class A coach where the rear A/C stopped working yet you could hear the relays click when the thermostat was lowered to start the AC. The voltage leaving the breaker was fine and I started the trace. Turns out there was a power terminal box under one of the closet drawers in the bedroom where there were 4 wires in a wire nut that had loosened and was sort of burnt that broke the connection to the A/C unit neutral. I pulled that apart and used two wire nuts and a jumper between them to use the proper size wire nut and tightened everything back up.


It's good practice to do a once a year "tighten the screws" electrical checkup as our rigs get bounced around on our wonderful roadways.


Tom
 
You have a lot of us baffled on this, so don't feel lonely. Some here have mentioned a ground issue. In the past, we had a grounding issue. The ground cable was corroded inside the cable causing a poor ground. When it was replaced, problem solved. But, we did not have solar.

Another question, on the battery photos, there is a blue coded terminal on the battery negative post, but no wire. Was it like that before the issue?
 
50 amp is 2 120vac circuits. Might you only have 1 120vac avaliable where you are plugged in?
 
Salad said:
Main (50 amp) Breaker Right Side: 0 volts Left Side: 120 volts
We have ordered a new Main (50 amp) Breaker to replace.
Click to expand...

I think you missed a critical point Larry was making. If you measured zero volts at the left side breaker terminal screw, then the breaker is NOT the problem. The problem is with the supply voltage somewhere.

The main breaker is a back-feed breaker. The INPUT is the terminal screws and it's OUTPUT is the lugs on the back which place power onto the distribution bus for input to the other breakers.
 
Last edited:
Salad said:
We are home at plugged into our house.
Click to expand...


Can you remind me exactly what you are plugged into at your house? Are you using an adapter to plug into a 15 or 20 amp outlet? If so then your adapter could be bad.

See post #7 here, and how a jumper works in an adapter to provide power to both hot legs in a 50 amp RV. Also read post #8 there if you are using a Y/cheater adapter by chance.


https://www.forestriverforums.com/f...ds-and-adapters-101-a-260696.html#post2964050
 
Last edited:
wmtire said:
Can you remind me exactly what you are plugged into at your house? Are you using an adapter to plug into a 15 or 20 amp outlet? If so then your adapter could be bad.

See post #7 here, and how a jumper works in an adapter to provide power to both hot legs in a 50 amp RV. Also read post #8 there if you are using a Y/cheater adapter by chance.


https://www.forestriverforums.com/f...ds-and-adapters-101-a-260696.html#post2964050
Click to expand...

We are plugged into a 15 amp outlet at our house using adapters. (Not the Y Cheater Adapter)
 
You must log in or register to reply here.

Similar threads

GL
Electrical Gremlin
GolfingDave
GO
20
Electrical issues help
2017Salem
20
MX
2021 Vengeance Rogue Shore plug issue
mxcamper555
MX
LM
No power at all
2
LMHNeace
LM
MC
Electrical Outlets all off line
bikendan
bikendan

New posts

Try RV LIFE Pro Free for 7 Days

  • New Ad-Free experience on this RV LIFE Community.
  • Plan the best RV Safe travel with RV LIFE Trip Wizard.
  • Navigate with our RV Safe GPS mobile app.
  • and much more...
Try RV LIFE Pro Today
Back
Top Bottom