MICTUNING Heavy Duty 7 Gang Junction Box Install Help

[StephenO]

Did you happen to complete this install Yoda? I too have the Mictuning junction box in my collection of stuff to install, but I've hit a similar situation as yourself with the number of negative wires under the marrette wire nut. In my install, there are 6 wires in there, one #10 to the 7way plug, one #10 to the frame, and 4 #14 (possibly #16) wires for the lights and brakes.

I've tried doing a "dry fit" with 6 ring terminals on the stud and it doesn't look promising, so I've been trying to see how to go about this, and wouldn't mind seeing your install if possible.

Currently I think my options are:
1) Try putting all 6 onto the stud, and hope it fits! Not sure though that I want any hoped based electrical connections in my trailer

2) Putting a bus bar on the outside of the Mictuning junction box, and put a jumper wire between that and the Mictuning negative stud. Then take the remaining 5 negative wires and connect them to the bar

3) If there is room, put a bus bar inside the Mictuning box along the top, and again installing a jumper, or move the 7way negative cable up to this new bar, followed by the remaining negatives

4) Do as Jlawles2 suggested and put an additional nut on the negative post. Did I read this correctly though, IE once installed you would have on the post half the rings, a nut, the other half of the rings, and then a final nut on-top? I've never done this, but wouldn't that mean the nut is now your current path between the two batches of rings?

If there are other ideas out there too, please chime in!

Thanks!

[Yoda]

Did you happen to complete this install Yoda? I too have the Mictuning junction box in my collection of stuff to install, but I've hit a similar situation as yourself with the number of negative wires under the marrette wire nut. In my install, there are 6 wires in there, one #10 to the 7way plug, one #10 to the frame, and 4 #14 (possibly #16) wires for the lights and brakes.

I've tried doing a "dry fit" with 6 ring terminals on the stud and it doesn't look promising, so I've been trying to see how to go about this, and wouldn't mind seeing your install if possible.

Currently I think my options are:
1) Try putting all 6 onto the stud, and hope it fits! Not sure though that I want any hoped based electrical connections in my trailer

2) Putting a bus bar on the outside of the Mictuning junction box, and put a jumper wire between that and the Mictuning negative stud. Then take the remaining 5 negative wires and connect them to the bar

3) If there is room, put a bus bar inside the Mictuning box along the top, and again installing a jumper, or move the 7way negative cable up to this new bar, followed by the remaining negatives

4) Do as Jlawles2 suggested and put an additional nut on the negative post. Did I read this correctly though, IE once installed you would have on the post half the rings, a nut, the other half of the rings, and then a final nut on-top? I've never done this, but wouldn't that mean the nut is now your current path between the two batches of rings?

If there are other ideas out there too, please chime in!

Thanks!

I have not gotten to it yet - still fighting the coroplast. However I was thinking of pairing them up, but it is a long run inside the box to the stud. Ill probably stare at it for a while then decide,

I am wondering why GD did not put a ground wire in the king pin box attached to the frame. The white negative returns wires are all return wires associated withe positive out wires to the lights. signals, etc. They all ground through the tow vehicle 7 pin plug. That's why when I did my DC-DC charger I did not disconnect the ground wire as some have done.. I am wondering if it would hurt to add a buss bar attached to the king pin box and then tie 1 - 10awg wire into the Mictuning. Food for thought.?

[howson]

Did you happen to complete this install Yoda? I too have the Mictuning junction box in my collection of stuff to install, but I've hit a similar situation as yourself with the number of negative wires under the marrette wire nut. In my install, there are 6 wires in there, one #10 to the 7way plug, one #10 to the frame, and 4 #14 (possibly #16) wires for the lights and brakes.

I've tried doing a "dry fit" with 6 ring terminals on the stud and it doesn't look promising, so I've been trying to see how to go about this, and wouldn't mind seeing your install if possible.

Currently I think my options are:
1) Try putting all 6 onto the stud, and hope it fits! Not sure though that I want any hoped based electrical connections in my trailer

2) Putting a bus bar on the outside of the Mictuning junction box, and put a jumper wire between that and the Mictuning negative stud. Then take the remaining 5 negative wires and connect them to the bar

3) If there is room, put a bus bar inside the Mictuning box along the top, and again installing a jumper, or move the 7way negative cable up to this new bar, followed by the remaining negatives

4) Do as Jlawles2 suggested and put an additional nut on the negative post. Did I read this correctly though, IE once installed you would have on the post half the rings, a nut, the other half of the rings, and then a final nut on-top? I've never done this, but wouldn't that mean the nut is now your current path between the two batches of rings?

If there are other ideas out there too, please chime in!

Thanks!

Door #2, Monty. (Let's Make a Deal reference for those who are confused.)

The Mictuning box on my rig has the negative 12v wire coming from the Bargman cable and then the -12v wire going to the camper going out. The third wire is for the DC-DC Converter (that's the small wires wrapped in the gray sleeve). The latter is the "trigger" for the Renogy when the lights in the truck (thus the marker lights on the camper) are turned on.



For the myriad negative 12v returns ganged up near this area there's a bus bar with four studs. All the wires (including the one that goes to the frame) are on the bus bar. (Shocking, I know, but I don't have a picture of that setup.)

Howard

[StephenO]

Thanks howson and Yoda

I was leaning towards option 2, so with your feedback looks like I am off to Amazon to get a busbar

Keith - with what you described, I do wonder how your brakes are connected. What I mean is, your brake negative connection should be somehow connected to both the negative going back to the truck for normal operation, and to the negative on your RV battery for the emergency breakaway. On our trailer, that is accomplished through the marrette connection, that has both the truck negative and a connection back to frame/battery.

[Yoda]

Thanks howson and Yoda

I was leaning towards option 2, so with your feedback looks like I am off to Amazon to get a busbar

Keith - with what you described, I do wonder how your brakes are connected. What I mean is, your brake negative connection should be somehow connected to both the negative going back to the truck for normal operation, and to the negative on your RV battery for the emergency breakaway. On our trailer, that is accomplished through the marrette connection, that has both the truck negative and a connection back to frame/battery.

Ok this is my stock connection box a the king pin The black wire between the two blue wires (right) feeds positive power to the breakaway switch as far as I know.. Now in the center top right of the picture way at the back you can see a glimpse of the blue wire going into a red sheath. Also in the red sheath to the white negative return the goes into the blue wire nut. To the best of my knowledge there is not a connection from the negative wire bundle to the frame. Nor am I sure how power gets from the breakaway switch to the breaks as the red sheath that supplies break power. Hmmm maybe one of the black wires behind is from the switch and ties into the 12v+ from the truck which is connected to the battery (red wire nut in center with red/white strip.

Howard howson Where does you brake away switch get power or to the brakes? I don't see it tied in you picture above.

When I get to this I will be using my multi-meter to figure out what hot, etc

That red wire with the white stripe comes from the distribution bar in the front bay and is tied to the 12V+ charge line from the 7 pin. I wonder if the black/white stripe is the power to the breakaway switch and from the switch is the black wires tied into the blue brake wiring.. If I don't get this done before the rally it will make for a good evening project there.

Well I got the coroplast up on the curb side above the tires, so now to the front and the cuts around the sewer line. Ill do that tomorrow morning when it is cool.and give this junction box another hard look.

[howson]

Yoda

The breakaway wiring is not part of the Bargman (7-pin) cable, nor is it tied into the Mictuning. At least it wasn't in my 315RLTS. I doubt it's wired much differently in 5vrs.

Below is how my trailer came wired. Look at the junction below the large number 1--that's the breakaway power (+12v) wiring. I drew it into the circuit diagram below (with switch).

OK 5vr owners...need some help here. Is yours different? Country Campers , ncitro , Cate&Rob ?



In reference to the statement To the best of my knowledge there is not a connection from the negative wire bundle to the frame I'd be very surprised if there's not a wire near the battery compartment that's connected to the frame. A multitude of 12V circuits use the frame as a big 'ol return wire to get back to the battery.

Howard

[howson]

Yoda

Based on how mine is wired, the large red wire at the top left of your wiring is from the battery bank. The black wire going out is the feed to your breakaway switch. (You'll have to verify.)



In my setup the output of the breakaway switch goes to the Hydrastar Disc Brake Actuator (powers the disc brakes). I don't remember how it was originally wired to the OEM brakes.

The circled gold stud is tied directly to battery power. +12V will go through the switch (when pulled) down the "yellow" wire to the brake actuator.

[Country Campers]

StephenO howson Yoda

Be careful all you are comparing fifth wheel with travel trailer, fifth wheels are much different.

I think StephenO needs to follow a travel trailer layout and not a fifth wheel layout.

I would go with your option 2, add a buss bar for the negatives. You might also want to get a dry box of some kind and move your auto resetting breakers into that and maybe have space for the ground bar. Having these items out in the elements is not the best, they corrode and cause issues after a while.

Brian

[howson]

StephenO howson Yoda

Be careful all you are comparing fifth wheel with travel trailer, fifth wheels are much different.

I think StephenO needs to follow a travel trailer layout and not a fifth wheel layout.

I would go with your option 2, add a buss bar for the negatives. You might also want to get a dry box of some kind and move your auto resetting breakers into that and maybe have space for the ground bar. Having these items out in the elements is not the best, they corrode and cause issues after a while.

Brian

It would be most informative if you will spell out the differences, Brian. I'm unfamiliar with how the 5vrs are wired.

[ncitro]

howson Yoda It's been a while since I did mine but I think my breakaway tired in up in the pin box. My connection to the frame was inside the front compartment. One of the wires on the ground on the umbilical when to the ground stud in the front bay.

The positives I'm no help, I abandoned that whole bar and replaced it with a fuse box.

[ncitro]

This is the fuse box I used.

[Country Campers]

Howard,

Fifth wheels do not have all of those grounds at the junction box. The break away switch does get its power and ground from the junction box, located right beside the break away under the pin box. All of the grounds that travel trailers have connected are inside the front storage of a fifth wheel, along with the self resetting breakers, so there is no large amount of grounds in the junction box. I think that is all, maybe.

This is why I say stick to travel trailer wiring and only pay attention to pictures posted from a travel trailer so one does not get confused.

Brian

[StephenO]

StephenO howson Yoda

Be careful all you are comparing fifth wheel with travel trailer, fifth wheels are much different.

I think StephenO needs to follow a travel trailer layout and not a fifth wheel layout.

howson Yoda

This is a good point for anyone coming into this conversation fresh, I have a travel trailer and the wiring is indeed not the same as fifth wheels.

For reference, the breakaway switch on our trailer gets its positive connection from the 'input' side of the auto reset breaker, and then the output of the breakaway goes to the junction box where it connects with the truck brake positive using a blade wire connector. The negative connection for the brakes returns to the junction box, connected to the marrette with all the other negatives, along with a jumper that goes to the frame / battery connection. Also under that marrette is the truck negative connection.

I would go with your option 2, add a buss bar for the negatives. You might also want to get a dry box of some kind and move your auto resetting breakers into that and maybe have space for the ground bar. Having these items out in the elements is not the best, they corrode and cause issues after a while.

Appreciate the feedback here, and I'll see what I can find for a dry box. When I recently upgraded the battery connections, there was certainly dirt and road dust collecting near the junction box and auto resetting breaker.

[Jlawles2]

StephenO Correct the 5er wiring is a bit different. As for the nut being the path of least resistance, that would be the last worry I would have. Once you properly tighten the nut it becomes and integral part of the stack.

I'd have to look at how I did run the wiring in the box (it's been a while) but a couple of the studs did have quite the mass of wiring on them. The 12V + was on as mentioned the 12V+ in from whip cord, break away, and out to the camper are all on one that I remember. The ground IIRC was a big mess of something that should have never passed.

[Jlawles2]

So I went out and pulled the cover off the Mictuning box. There are indeed 5 wires on the post for one of the connections. And there is plenty of thread left.


The other day I made a leap. Cut the cord:



I now have a short true whip cord with the same end. The plug is installed on the cross member of the pin box, the whip cord plugs into the truck and the connector on the trailer. No more wrapping the cord and shoving it in the pin box. Long term I plan on getting a coiled cord to make the connection.