Un-Planned, Un-wanted electrical modification

T3XX

Member
About the 2nd day into a 4.5 day trip our A/C (dometic) shut off during use.
Some light troubleshooting led to testing continuity between the breaker and the A/C box that holds the relay. The hot (black) wire of the romex failed continuity, but the other 2 wires tested fine. 12 volt and thermostat were still working. The relay would click on and off. Continuity also passed for the breaker when in the on position.
We packed up the next day and headed home (bummer).

Got the rig back home and finished searching for this break in the hot wire of romex between the breaker and A/C box. I ended up pulling the microwave out and finding a cheap (no skill required) friction junction box that seemed to have failed.

5fc1b70166ea54d9c13bf475210100db.jpg


7c1fdc8644007edc6b391ab259e7eb8e.jpg


The cap to this device only had 2 of the four barbed arms(?) that were still secured to the device/box.

Hoping if anyone has the same symptoms and can get their hands on a voltmeter with continuity mode they can salvage their trip.

I put in a different junction box with a much better connection method, taped, labeled, and screwed back to the interior wall. Not before spending many hours pulling panels and various other troubleshooting steps…


Cheers,

-Colin
 

Hollandt

Well-known member
About the 2nd day into a 4.5 day trip our A/C (dometic) shut off during use.
Some light troubleshooting led to testing continuity between the breaker and the A/C box that holds the relay. The hot (black) wire of the romex failed continuity, but the other 2 wires tested fine. 12 volt and thermostat were still working. The relay would click on and off. Continuity also passed for the breaker when in the on position.
We packed up the next day and headed home (bummer).

Got the rig back home and finished searching for this break in the hot wire of romex between the breaker and A/C box. I ended up pulling the microwave out and finding a cheap (no skill required) friction junction box that seemed to have failed.

5fc1b70166ea54d9c13bf475210100db.jpg


7c1fdc8644007edc6b391ab259e7eb8e.jpg


The cap to this device only had 2 of the four barbed arms(?) that were still secured to the device/box.

Hoping if anyone has the same symptoms and can get their hands on a voltmeter with continuity mode they can salvage their trip.

I put in a different junction box with a much better connection method, taped, labeled, and screwed back to the interior wall. Not before spending many hours pulling panels and various other troubleshooting steps…


Cheers,

-Colin
I think this is the second occurrence of this I have read about on the forum in the last 30 days with the same issue. It appears that is has becomes common for the manufacture to make this junction of the AC feed rather than make a home run feed to the power box.
 

wdk450

Well-known member
Look at the picture and think about how little metal-to-metal contact area there is where the metal V's and the wires connect. Compare that contact area in your mind, to that of a metal screwhead and metal plate (like on a standard outlet) to a stripped Romex copper wire. Then add to that all of the road vibration to the connection while travelling; and the non Quality Assurance inspecting of RV electrical systems on the production line.
I just don't understand how these Insulation Displacement Connectors ever got UL approval. I have changed out all of my wall outlets to standard screw - type outlets. I don't think my 2008 production rig had this IDC interconnect point, but I will look for it.

What did you use to replace the IDC interconnect box, a box with a screw terminal strip inside???
 

mlpeloquin

Well-known member
What I had found is that a lot of the electrical boxes had wire not fully pushed down the the base of the insulation displacement connector. I went through the entire RV and replaced some and fixed others. One thing to look for is the corded wire that brings AC into your slides. On two of mine I had to replace the cord, no small job, and make sure that the wire is not installed as to have the insulation scrubbed off when you open and close the slides. They come from the junction box under the slides and enter the slide on the underside left or right side. Mine had the external jacket, neutral, and ground insulation stripped off and was working its way through the cord. Just by chance the hot was closet to the bottom of the slide.
 

Dahillbilly

Well-known member
I'm surprised that this type of connection is even allowed by some code? Going to keep close eye on those outlets with higher amp draw ex: toaster, coffee maker.
 

wdk450

Well-known member
I'm surprised that this type of connection is even allowed by some code? Going to keep close eye on those outlets with higher amp draw ex: toaster, coffee maker.
I first noticed that I had an outlet problem NOT by complete electrical failure of the outlet, but when I had my electrical space heater plugged into the outlet, heat on; fan still ran and it seemed to heat OK, but I noticed that the pilot light was blinking rapidly (due to an arcing connection inside the IDC outlet). Replaced IDC outlet with standard household outlet, and space heater pilot light blinking was gone.
 

T3XX

Member
Look at the picture and think about how little metal-to-metal contact area there is where the metal V's and the wires connect. Compare that contact area in your mind, to that of a metal screwhead and metal plate (like on a standard outlet) to a stripped Romex copper wire. Then add to that all of the road vibration to the connection while travelling; and the non Quality Assurance inspecting of RV electrical systems on the production line.
I just don't understand how these Insulation Displacement Connectors ever got UL approval. I have changed out all of my wall outlets to standard screw - type outlets. I don't think my 2008 production rig had this IDC interconnect point, but I will look for it.

What did you use to replace the IDC interconnect box, a box with a screw terminal strip inside???

I am not a licensed electrician so I’ll refrain from sharing all the details, but it is a mechanical connection and then taped, inside a plastic housing that I screwed to that back wall.

I’m not sure how those got approved either.
The application of these “IDC” boxes I’m sure could be used somewhere…but a rolling home …sheesh.
This is a 2017 Mallard M26.

The only thing I’m grateful for is that it ended up being in a really easy location to work on (once I found it).


Cheers,

-Colin


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