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Adapter for 7 pole rv to 4 pole round?

brandonrv
Explorer
Explorer
I got my jeep wired so that I can plug directly into the front of it when I'm towing. Problem is they installed a 4 pole round connector in the front, but I've got a 7 pole RV connector on the RV.

Anyone know an adapter for this or do I have to go get the RV wired for 4 pole round now?
2014 Fleetwood Bounder 35k
24 REPLIES 24

tropical36
Explorer
Explorer
brandonrv wrote:
Yeah I've got the adapter. Looks like the 7 pin side is right but the 4 pin side is not right. I guess I should try to wire it myself. How can I tell what the 4 pin is set up to on my Jeep? I assume I just have to match colors?

Lay a battery on the ground after first establishing which pin is ground with an ohmmeter. Connect the neg side of the battery to this ground pin or just try the toad frame. Then touch each pin other than the ground with the battery pos to see what lights up on the toad. Make a drawing of same.
The same can be done with a meter at the end of the umbilical and turning things off and on in the coach. Whichever is easier can be changed to match.
"We are often so caught up in our destination that we forget to appreciate the journey."

07 Revolution LE 40E_Spartan MM_06 400HP C9 CAT_Allison 3000.

Dinghy_2010 Jeep Wrangler JKU ISLANDER.

1998 36ft. National Tropi-Cal Chevy Model 6350 (Sold)

DougE
Explorer
Explorer
Since the present hookup is not working right, worrying about color coding on the jeep side is probably futile. Just cut the wiring. Take a spare battery and ground it to the jeep frame with a jumper cable. Use a test light hooked to the positive battery terminal to probe the 4 wires. When you get continuity without any glow from the parking lights, you have identified the ground wire. Then use a jumper cable from the positive battery terminal to identify the remaining 3 wires. Park, left turn and right turn should be obvious.
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gatorcq
Explorer
Explorer
On my rig, I installed a 7 pin blade on the Alfa, and a 5 pin round on our jeep. This gave me the following lights.
Left / Right Turn signal (Amber)
Parking lights (Red)
Braking/emergency (Red).

These are all separate lights on the Jeep Liberty.
I already had the umbilical cord (7 Blade to 5 round).
The Alfa came pre-wired with the 7 blade. I have diagrams from Etrailer showing the standard wires charts.
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brandonrv
Explorer
Explorer
Yeah I've got the adapter. Looks like the 7 pin side is right but the 4 pin side is not right. I guess I should try to wire it myself. How can I tell what the 4 pin is set up to on my Jeep? I assume I just have to match colors?
2014 Fleetwood Bounder 35k

wny_pat1
Explorer
Explorer
tropical36 wrote:
brandonrv wrote:
I got my jeep wired so that I can plug directly into the front of it when I'm towing. Problem is they installed a 4 pole round connector in the front, but I've got a 7 pole RV connector on the RV.

Anyone know an adapter for this or do I have to go get the RV wired for 4 pole round now?

Are you saying that you have a 7 to 7 umbilical cord? If that's the case and since I like having spares, I'd just replace the four on the toad with a 7 to match. If not and don't like doing these things for yourself, COOLTECH has a 7 to 4 umbilical cord already made up.
Tropical36, you missed the part where he tried a 7 pin to 4 pin adaptor and it still didn't work. I'm thinking a good old fashion test light at the 7 pin outlet on the motorhome to figure out what each pin is for, and then working his way back to the toad. I just go the the local hardware store, buy my cord cut to length, and wire it myself. That cuts my cost in better than half of what the special made cords cost.
“All journeys have secret destinations of which the traveler is unaware.”

tropical36
Explorer
Explorer
brandonrv wrote:
I got my jeep wired so that I can plug directly into the front of it when I'm towing. Problem is they installed a 4 pole round connector in the front, but I've got a 7 pole RV connector on the RV.

Anyone know an adapter for this or do I have to go get the RV wired for 4 pole round now?

Are you saying that you have a 7 to 7 umbilical cord? If that's the case and since I like having spares, I'd just replace the four on the toad with a 7 to match. If not and don't like doing these things for yourself, COOLTECH has a 7 to 4 umbilical cord already made up.
"We are often so caught up in our destination that we forget to appreciate the journey."

07 Revolution LE 40E_Spartan MM_06 400HP C9 CAT_Allison 3000.

Dinghy_2010 Jeep Wrangler JKU ISLANDER.

1998 36ft. National Tropi-Cal Chevy Model 6350 (Sold)

DougE
Explorer
Explorer
All Hopkins connectors are wired to the most generally accepted standard configurations. Go to the Hopkins site and print out their wiring diagram. Check your 7 way on the MH to their pattern. It should check out. More likely is the 4 way round as there is no generally accepted standard for 4 ways.
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Johnny_G1
Explorer
Explorer
Talk about Dingbats, Newmar has some of the best, they hung a bunch of wire off the original coach rear marker and tail light wires, but the only problem they just used 7 different wires that don't match to any wire code, most 7 wire cords are know for their colors and easy to hook up to any plug or socket.Have to start all over again to put a new 7 wire plug on, where there was only a 4 wire for the toad?????
98 Mountain Aire 34' 210 Cummins Puller and 2001 dodge dully with all the toy's, 400 + hp pullin a 2001 32.5' Okanogan 5th wheel, new to us after 5 yrs with the 28' Travel Aire. Lots of fun.

FIRE_UP
Explorer
Explorer
brandonrv wrote:
FIRE UP wrote:
brandonrv,
Yes Sir, they make adapters for 7 pin RV plugs to any configuration you want, 4-pin flat, 4-pin square, 4-pin round, 5-pin round, 6-pin square and more. DO NOT CHANGE THAT PLUG ON THE RV!! It's most likely wired by the factory and is well done and to national color coding and pin placement. It might be useful at a later date when you might wand to hook up a larger trailer etc.

One of the first things you must do is, make sure that the wiring/pin arrangement in your seven pin RV plug is configured so it will match up to the 4-pin round correctly. We've owned four different RVs, (2) Class Cs, and (2) Class As. All four came from the factory with 7 pin plugs. As did and does, about 99.9999% of all the pickups sold in America.

Most of your adapters can be found at Camping World, or any other well supplied RV Supplies outlets. One of the nice things to have around is an "LED", 7-pin plug checker. I just got one from a local swap meet for about $5.00 and man, is it great. You can check the out put right at that plug and see if all is good every now and then.
Scott


Thanks, scott. Maybe that's the problem with my adapter. The pins don't match up. I'll look at getting one of those 7 pin testers. Maybe I can figure out how to rewire it.


brandonrv.
So many folks make this too hard. It's incredibly simple. If you don't have the experience or the tools to do some trouble shooting, then maybe a neighbor or a friend could lend a hand. Like I stated, DO NOT CHANGE THE 7 PIN ON THE COACH! It does sound like the company that did the Jeep wiring for you was clueless. We've owned (7) of those darned Jeeps and you can wire them blind folded and not screw up.

Those testers I told you about only test them, they do not tell you what pin is what. If you have a 12V test light, (they're cheap if you don't have one) you clamp the wire on a known good ground, then, with the help of an assistant, like the DW or friend, have them:

1. Turn on Running lights, check which pin it is in the 7 pin plug
2. Turn on the ignition, and a right turn signal, check which pin
3. " " " " " " Left " " " " "
4. " " " " Check if you have a "Reverse" wire/pin

Now, this is where it gets only a tad more difficult. If you have amber turn signals, then you may, I say MAY, have a separate brake light wire/pin in the 7 pin plug. If you don't have amber turn signals on the coach, then each turn signal pin will also act as brake light signal too.

And, just in case either the factory or, the previous owner got their little hands in there and did some pre wiring before that plug, and, you've got amber turn signals, you could also have a "Tail light" converter which, combines the turn signal and the brakes in each pin. If, you don't have amber turn signals, you still will have a combined turn signal/brake light for each side. The remaining pins are for ground and a possible wire for electric brakes. But for your Jeep, all you need is four wires. One for "Tail marker" or, (running lights as we old timers call them), one for the right turn signal/brake, one for the left turn signal/brake and one for ground.

When you get your tests done and , noted on paper, then just match them up on the four wire/pole adapter. Now, this all presupposes that the dingbats wired the Jeep correctly. Too bad you're not near me, I'd come over and get it done in about 20 minutes for you. Good luck.
Scott
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gone2dadesert
Explorer
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Tom_Barb
Explorer
Explorer
Manufacture a connector cable by using the parts from NAPA, a 6' length of 4 wire cable a 4 pin female connector, and a female 7 pin connector to fit the RV..

the silver pin in the 4 pole connector is ground to the RV ground pole.
the brass pin directly across from the silver pin is parking lights, the other 2 are L/H and R/H brake and signal lights. as wired in your Toad.

this shows the 7 pin connectors
7 pin wire diagram for trailerhttp://vimeo.com/39205694
This may also help
http://www.etrailer.com/question-27196.html
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wny_pat1
Explorer
Explorer
My Blue Ox baseplate came with a 7 pin plug for the front of the toad. Already had a 7 pin plug on the back of the coach. Don't know what Roadmaster and the others supply with theirs.
“All journeys have secret destinations of which the traveler is unaware.”

Francesca_Knowl
Explorer
Explorer
brandonrv wrote:
Mandalay Parr wrote:
Can you remove the 4 pole round and wire in a 7 round?


I can't.. I'm sure I could pay someone to do that. I took my jeep to a motorhome dealer to do the wiring for me. Figured they knew what they were doing.

Got home realized it doesn't hook up. Got online can't find many adapters. Found that Hopkins one and bought it. Doesn't do the trick.

This 4 pole round is sort of a mystery.

Have you tried going back to the RV place that did this recent wiring?

Surely they could advise you as to the correct connector, and especially since you've already tried an adapter it may be that the wiring is wrong for your situation.
" Not every mind that wanders is lost. " With apologies to J.R.R. Tolkien

Doug_and_Cassi_
Explorer
Explorer
Wal-Mart sells the adapters.