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Discussion Starter · #1 ·
I searched for a little while and didn't find anything too much in detail.

Most of the trailers i want to tow have 7 pin connectors. How hard and or what is all entailed to convert the 4 pin into a 7 pin???
 

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FJ Expeditions R Us
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The 7-pin RV connector contains wires for a hot 12v, electric brakes, etc. They do make convertors to go from 7 to 4 and I think 4 to 7.

cheers,

dale
 

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I searched for a little while and didn't find anything too much in detail.

Most of the trailers i want to tow have 7 pin connectors. How hard and or what is all entailed to convert the 4 pin into a 7 pin???
This isn't the hardest mod to do but it does involve some additional wiring and tapping into wiring on the FJ. First you need to have the FJ trailer converter and wiring harness (can be done with aftermarket -way harder and some who have done it have reported problems with FJ electronics). The 7-pin RV connector is probably what you're seeing on the trailers. In addition to the GROUND, TAIL LIGHT, LEFT TURN and RIGHT TURN (STOP LIGHT is created by the FJ converter using both of the turn signals) the 7 pin connector adds an AUX circuit from battery (20-30 amp), a REVERSE/BACKUP LIGHT circuit (this also releases some types of hydraulic trailer brakes) and most importantly an ELECTRIC BRAKE circuit. To get a fully functioning 7-pin connector wired on your FJ you have to also add a Trailer Brake Controller. If your trailers do not have Trailer Brakes you can just wire the 7-pin Socket to the FJ trailer harness. They make 7-pin Sockets that have a pre-wired 4-pin connector built in and all you would have to do is cut off the FJ 4-pin connector and land the wires on the 7-pin Socket. Everything is already labeled. Finding a place for the 7-pin Socket where it won't get ripped off when 4 wheeling not easy. The instructions that come with Brake Controllers are pretty easy to follow and you can run the wires from the Jack Storage area to the front of the FJ without tearing apart the plastic panels.
 

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Discussion Starter · #5 ·
Most wakeboard boat trailers have surge brakes on them. But they still have the 7 pin connector. So no brake controller is needed for what i am towing. But, it sounds pretty involved. I wonder why no one has offered some sort of "kit".

Thanks for the replies guys (possibly gals). It does seem that there is more to it than just some extra plug though. I will do some product searching.
 

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Most wakeboard boat trailers have surge brakes on them. But they still have the 7 pin connector. So no brake controller is needed for what i am towing. But, it sounds pretty involved. I wonder why no one has offered some sort of "kit".

Thanks for the replies guys (possibly gals). It does seem that there is more to it than just some extra plug though. I will do some product searching.
Google 'brake controllers' almost all the places that sell them have pdf versions of the install instructions and you can see what wiring is involved. The AUX and REVERSE circuits are less critical although some trailers use the AUX circuit to keep the break-away battery charged. As long as the trailers you tow don't have electric brakes buy a 7-pin Socket and a short 4-pin extension cut the female end off and wire the male 4-pin cable into the 7-pin Socket. The 7-pin Socket will be labeled and the 4-pin wires are color coded and sometimes labeled as well. The &-pin Socket will have at least 2 holes for mounting it into a bracket which you could use with a piece of rope or velcro tie to secure it to the trailer frame if you don't want a permanent mount.
 

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I found a 7 pin plug at Walmart that you can plug your 4 pin connector into. Then there are leads to wire your brake controler into if you are using one.
It was about $25.00 and I was able to use the factory bracket. It also has the 4 pin plug on it.

Amazon.com: Hopkins Plug-In Simple 47185 Multitow 7:4 Adapter: Automotive

Hoppy Part #47185
I have this exact 7 pin plug and it works for me.Simple plug the existing4 pin flat to the adaptor plug then run a 12v fused hot from the battery and you good to go.
 
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