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Changing Electrical cord from 7 round to 7 flat - How to?

Baja_Man
Explorer
Explorer
The 1998 Jayco 243rks I just purchased has a 7 pin round electrical connector. My truck has the 7 blade standard RV style. I can find an adapter or change out cord with a new 7 blade style connector.

Has anyone ever changed one these and can provide tips in how to do it? I can always go the adapter route, but it would be nice to have the correct plug without the use of an adapter.

Thanks
2023 GMC, 3500HD, Crew Cab, 6.6L Gas/6 Speed Auto, 4X4, Standard Bed; SRW
2011 Outback 250RS - Anniversary Edition
Equal-i-zer 10K
16 REPLIES 16

time2roll
Nomad
Nomad
Baja Man wrote:
Can't I just use remove the wires from the old plug and place them into a new 7 blade plug? In the pics posted, the wires are set into terminals with set screws. Am I correct?


You could get fancy with some heat shrink ring terminals.
Otherwise yes you remove a wire and secure it to the new connector.

Baja_Man
Explorer
Explorer
Plug on my Jayco appears to have been changed from original. It is a Cole-Hersee plug with 7 pin round. I bet original owner changed it to match his older Dodge Ram diesel plug. In a pic I saw with the trailer and truck, it appeared to be a late 80s early 90s Dodge Ram diesel. Older trucks had 7 pin round. How do I know...my 1992 Ford had one that was OEM until I changed it to a 7 flat blade.
2023 GMC, 3500HD, Crew Cab, 6.6L Gas/6 Speed Auto, 4X4, Standard Bed; SRW
2011 Outback 250RS - Anniversary Edition
Equal-i-zer 10K

Baja_Man
Explorer
Explorer
Can't I just use remove the wires from the old plug and place them into a new 7 blade plug? In the pics posted, the wires are set into terminals with set screws. Am I correct?
2023 GMC, 3500HD, Crew Cab, 6.6L Gas/6 Speed Auto, 4X4, Standard Bed; SRW
2011 Outback 250RS - Anniversary Edition
Equal-i-zer 10K

Old-Biscuit
Explorer III
Explorer III
smkettner wrote:
I would put a new plug on with the flat blade connectors.
No adapters unless you are just towing it someplace to sell.


X2

Just more connections to corrode/cause resistance......doesn't take much to stop 12V DC

And for $3 more you can get a new trailer cord or for just $6 put a new 7 blade plug on trailer cord

Fewer connections......better connection

And trailer is now up to date for towing by your truck, your friends truck, neighbors truck, my truck :B
Is it time for your medication or mine?


2007 DODGE 3500 QC SRW 5.9L CTD In-Bed 'quiet gen'
2007 HitchHiker II 32.5 UKTG 2000W Xantex Inverter
US NAVY------USS Decatur DDG31

time2roll
Nomad
Nomad
I would put a new plug on with the flat blade connectors.
No adapters unless you are just towing it someplace to sell.

AZ_T_T
Explorer
Explorer
Baja Man wrote:
Thanks for the replies.

What are the thoughts on using an adapter that goes from 7 pin round to 7 pin flat? Like this one....

7 round to 7 flat adapter


Seems like the easiest solution and not priced too bad. I would try it.
AZ T&T
2012 Jayco Eagle Super Lite 29.5RKS
2011 Chevy 2500 HD 4x4 Duramax
B&W Companion Hitch - Firestone Ride-Rite Air Bags
Honda EU2000i Generator

colliehauler
Explorer III
Explorer III
RustyJC wrote:
The OP wants to change the trailer to the NEW style industry-standard Pollak 7-pin flat, which I'd highly recommend in case he ever needs anyone else to be able to tow the trailer.

I'd be careful and chase each wire since the 1996 and 2000 Jayco Designer 5th wheels I owned came with the Pollak 7-pin flat. If the Jayco you're looking at has a 7-pin round, that's non-standard for the Jayco and there's no telling how the previous owner had his truck wired.

Here's Pollak's standard for a 7-pin round:



Here's Pollak's standard for a 7-pin flat:



Rusty
My bad I thought the trailer had the flat and truck round. I never owned a trailer that did not have the flat blade's.

Baja_Man
Explorer
Explorer
Thanks for the replies.

What are the thoughts on using an adapter that goes from 7 pin round to 7 pin flat? Like this one....

7 round to 7 flat adapter
2023 GMC, 3500HD, Crew Cab, 6.6L Gas/6 Speed Auto, 4X4, Standard Bed; SRW
2011 Outback 250RS - Anniversary Edition
Equal-i-zer 10K

AZ_T_T
Explorer
Explorer
Should be a pretty straight forward job. If you have a 12v tester it will help.
AZ T&T
2012 Jayco Eagle Super Lite 29.5RKS
2011 Chevy 2500 HD 4x4 Duramax
B&W Companion Hitch - Firestone Ride-Rite Air Bags
Honda EU2000i Generator

Tennessee_Nomad
Explorer
Explorer
Old-Biscuit wrote:
Take pics of old wire connections BEFORE disconnecting wires........:B


Good advice!
2010 Keystone Montana 3455SA Quad Slide
4 Goodyear G614's
2017 RAM 3500 DRW 4x4 Crew Cab
6.7L Cummins® Turbo Diesel
B & W Companion Hitch
All Made In USA

*I chose the road less traveled... Now I don't know where the hell I am*

Hiking_Hunter
Explorer
Explorer
.
Amateur Radio WA4GIY
2015 Montana High Country 305RL
2013 RAM 3500 4x4, crew cab, long bed, 6.7 CTD, Aisin trans.
CGVW 20460 Lbs.

RustyJC
Explorer
Explorer
The OP wants to change the trailer to the NEW style industry-standard Pollak 7-pin flat, which I'd highly recommend in case he ever needs anyone else to be able to tow the trailer.

I'd be careful and chase each wire since the 1996 and 2000 Jayco Designer 5th wheels I owned came with the Pollak 7-pin flat. If the Jayco you're looking at has a 7-pin round, that's non-standard for the Jayco and there's no telling how the previous owner had his truck wired.

Here's Pollak's standard for a 7-pin round:



Here's Pollak's standard for a 7-pin flat:



Rusty
2014.5 DRV Mobile Suites 38RSSA #6972

2016 Ram 3500 Dually Longhorn Crew Cab Long Bed, 4x4, 385/900 Cummins, Aisin AS69RC, 4.10, 39K+ GCWR, 30K+ trailer tow rating, 14K GVWR

B&W RVK3600

colliehauler
Explorer III
Explorer III
I would just change the plug on the truck to the same as the trailer. You can get the socket with wires at Tractor supply or off the internet. If you change the trailer to the old style and have to upgrade the truck you will be in the same boat again with the old style connector on the trailer.

laknox
Nomad
Nomad
Buy a flat/round pin adapter? :h

Lyle
2022 GMC Sierra 3500 HD Denali Crew Cab 4x4 Duramax
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