Dual 7-pin plugs??

[dcheatwood]

Need some tech help here.
I have a factory installed, 7-pin plug on the bumper of my tundra, and when I bought my first 5th wheel, they added a 7-pin in the bed of the truck. Up until now I never used the factory plug on the bumper.
Now I occasionally tow a 16' cargo trailer and just noticed the brakes do not work on the trailer when plugged into the bumper outlet.
I had an electrician look at it and he determined that the brake lead to the factory bumper outlet had been cut to accomodate the in-bed plug for the 5th wheel. He indicated that the brake controller may not be able to operate correctly with 2 brake leads connected.
Any truth to this? Or was the lead cut simply to reconnect to the new in-bed plug?
I'm just trying to figure out the best way to have braking on either plug.
Options are . .
1. Running a jumper wire from the in-bed plug to the bumper plug.
2. Installing a switch that can will provide power to only one plug at a time.
3. Spending @ $60 for an extension that will reach over the tailgate to the in-bed plug.
Thoughts???

[Narboza]

I recommend you wire both plugs correctly and use one at a time.

[dcheatwood]

"I had an electrician look at it and he determined that the brake lead to the factory bumper outlet had been cut to accommodate the in-bed plug for the 5th wheel. **He indicated that the brake controller may not be able to operate correctly with 2 brake leads connected.**

Hoping someone here can shed light on what the "correct" way is.
I certainly want to do as you suggest and have them both connected correctly if possible.

[AquaMan]

I had 2 outlets on my Sierra truck, stock bumper and one in the bed (which I installed). Both had full function and worked flawlessly. There is nothing wrong with having 2 connectors. The dealer just cheated and cut the wire.

[5picker]

I'm not sure why the original installation folks 'cut' only the brake controller wire to accommodate the second plug. If they successfully jumpered the wiring harness to the factory plug for all the other circuits, I have no idea why they would have not jumpered the brake wiring as well?? I've done this very thing (jumpering from one harness to another plug) several times with zero problems.

I see no reason why you couldn't add back a jumper from the in bed plug to the factory bumper plug for that circuit.

Yes, while I agree the brake controller couldn't handle supplying current to two 7 pin plugs simultaneously, (both connected to a trailer) just how in the world can you (or why would you) ever use both plugs at the same time? You are only going to use one or the other, not both together.

Go with your option # 1.

[Flybob]

Originally Posted by dcheatwood

"I had an electrician look at it and he determined that the brake lead to the factory bumper outlet had been cut to accommodate the in-bed plug for the 5th wheel. **He indicated that the brake controller may not be able to operate correctly with 2 brake leads connected.**
.

I would not let that electrician touch my unit. The controller will not operate properly if you have a trailer connected to both plugs at the same time, but as long as one plug is 0empty. the controller will never know. Run a wire from the good plug back to the bumper plug and you will be fine.

[dcheatwood]

Ok. Sounds like I made a good decision not buying a $69.00 extension wire. Thanks guys for the thoughts. I love it when all agree. Now if these afternoon rains hold off a while I'll get that jumper installed.

5picker, it's confusing to me too. All lights work on the bumper plug so it's all wired up from factory, but the brake wire was cut and pulled up into the fender for the in-bed plug. ?????? Hope I got this figured out now.

Flybob, that "electrician" just happen to be standing nearby while I was telling a friend about the issue. He dove under the truck with his multi tester to confirm current and saw the wire cut. He will Not be wiring the plug for me. Lol.

[thebrakeman]

Let's not be too hard on the electrician. He was hired to do a job:
"Why aren't the brakes working when plugged into the rear socket."
He answered that question, "Because somebody cut the wire", and was certainly paid for his time.

Did the OP ask for a thorough solution? Was the electrician even asked to do the rewire? Doesn't sound like it. I think the suggestion was thrown in for free. Since he's likely not an RV expert, and may not have dug into the system far enough (based on the original statement of work), he suggested a possible reason for why the wire was cut. That does not mean the electrician would have done that himself, or would recommend leaving it that way.


[Edit after reading last post...]
Even more so, they guy did the entire job for free, just being a nice guy!!
Even more reason not to ding the guy.

[ben31]

I had that same issue. The problem was the adapter. It had a bad pin in it for the brake control cable. I bypassed the sdapter and it worked fine. I called the manufacturer and they sent a replacement. The replacement worked fine.

[dcheatwood]

Found the problem. Brake lead was not cut. It was connected to both plugs. Had power all the way to where the blue brake wire entered the bumper plug, but not at the pin in the plug. That pretty much narrowed it down to inside the plug. I managed to get access to the rear of the plug and lightly pulled on the blue wire. It easily came out of the plug. The female connector was burnt and corroded and could not pinch the male part any more. I replace the female, scrubbed the others connectors good and tested. All is well.
Thanks again for the pointers.

[dcheatwood]

thebrakeman.
Guess I did sound a little hard on the free help from the electrician. He was a nice guy but nowhere near me now so he wouldn't be doing any work on it for me. However, now I wonder why he told me the wire was cut when it wasn't. ??? All's well that ends well. 🇺🇸

[Bama Rambler]

Thanks for coming back and letting us know what you found.

It is interesting that he told you that the wiring was cut.

[Narboza]

Maybe the electrician was hoping you would ask him to "fix" the cut wiring.