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Discussion Starter #1 (Edited)
I am about to get a small travel trailer,my 2011 FJ has the oem hitch and the 4 pin spade wiring. I purchased a Curt 57672 Duplex Electrical Adapter .
I watched this Video and feel confident in doing this myself. The local shop wanted almost $1000.00 bucks to do this they said I need a battery isolator for the trailer to have power. The guy in the video used 2 breakers, a 20A for the EBC power and a 30A for the trailer Tow power. I would rather use a 20A and 30A inline fuse in this process, also why would I need a isolator like the local shop suggested?

I am assuming the vehicle will be charging the trailer battery so will I need to get the FJ diode fuse off of ebay to make sure the alternator charges the trailer battery sufficiently?

What do you guys think?
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I will be picking the new travel trailer up on Feb 22, 2020 my first camper trailer, always tent camp or car camped. trailer is 2020 ForestRiver Flagstaff E-Pro 16BHG
 

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$1000 seems high. However, sometimes jobs are price to discourage their acceptance when the shop would rather not do it.

For trailer brakes you will want to use an automatically resetting breaker. If the breaker trips you may need to brake your trailer before you’ll have a chance to manually reset it - or replace the fuse.

You will also need to careful where and how you connect to the electrical system as some circuits rely on a reference voltage or amperage. The draw from a tapped in circuit can cause other problems.

I wouldn’t skimp on the trailer brake installation. Safety first! That said I would get estimates from some other shops.

Bonus suggestion - the 7 pin connector will support backup lights. This is usually not wired on the tow vehicle side, and most campers don’t have backup lights.
However you can solve both!
Find a good shop (or do it yourself) ask them to wire it as well.
Add backup lights to your camper and wire to the plug.
Profit! ...er, never have to struggle to back your trailer in the dark.
 

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As I understand it, for towing and trailers you might prefer a (self-resetting) breaker over a fuse in case it ever does trip due to something temporary, you won't have the connection to your brakes burned out until you can stop and replace a fuse (good luck stopping!), but just temporarily disconnected. I think the thinking is trailer brakes are important in a way that, say, air conditioning isn't, so you splurge on the cost and the space to put a resetting breaker instead of a fuse.

You might want a "battery isolator" so that when the vehicle is not running, the trailer cannot continue to draw power from the FJ's electrical system (your main, starting battery) and potentially leave you drained and unable to start back up. If you just wire from your main battery out the back to the tow connector, those circuits won't shut off when you turn off your engine. For some electrics you can work around this by tapping existing fuses in fuse boxes that are already switched with the engine, but 30A is usually a bit more than you want to tap on top of an existing circuit. You'd prefer to take that right off the battery terminals, but then you need to roll your own solution for breaking the connection when the engine (alternator, really) isn't running.

You have two choices, really, for doing that - a relay (a switch that is operated by a smaller electrical current) or a diode (object that only lets current pass through it in one direction). 30A is an unusually high rating for a diode, but automotive relays are common all the way up to 60-80A for just a few dollars a piece.

You shouldn't have any problem wiring up the actual tow connector. If you can, I would recommending actually using the properly-colored wires for each pin when you hook them up, so that if you (or someone else) ever has to service the connector, they don't have to use a multimeter to test every wire when reassembling to make sure they got it right. This may mean buying a bunch of spools of colored wire if you don't just keep a set on-hand.

$1,000 is a lot unless they're going to do a factory-quality job, IMO. But... I think the only "My FJ caught fire, like actually on fire" stories that I've heard have been from towing electrical issues. So, maybe it would be worth if you're really uncomfortable attempting it yourself. Do you think they'll do a factory-quality job? If not, don't pay 'em $1,000, IMO.
 

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That DIY video is good. The drawing was right on with what I have, just a different brake controller.

I have the 20A and 30A breakers, a Primus IQ controller and a Hopkins flat 4 to 7 round dual adapter, similar to the Curt unit.

Plug the OEM flat 4 into the back of the adapter and run the 3 other wires. The Brake controller has to T tap into the brake wire under the dash that's coming off the OEM harness module = Yellow circle. The RED circle is the OEM trailer harness module.

"Quality" work, not from any Camping World RV location. The guy ran the power wire past the Cat and didn't tie it off. Coming down the west side of the Continental Divide, towing a 3000+# trailer, the wire melted, popped the 30A right out of it's holder, it hit the underside of the hood and I had no trailer brakes.

And make sure they actually strip the wire before making the connections. :unsure: I had to re-do them all and added heat shrink tubing.

Diode, no. The best Battery Isolator is unplugging the 7 round when you arrive at your destination. The trailers battery should be charged by then. My trailer had a Zamp Solar Port to plug in panels that you can move around.

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1k is way high on price. I had a local shop in my area do it for 300. And they did a great job. I would of done it my self but don't trust my eyes since I'm color blind in a lot of colors.
I had my prodigy p3 wiring brought to my drivers side fuse cover. Then i bought a spare cover and mounted it to that cover. That way i can take it out after every trip.
 

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i have my controller mounted to a home made cup holder mount. i stick it in the front cup holder and i have it wired with a standard 4 pin trailer plug. the plug stays tucked up under the dash when i'm not using it.
i have a round plug for my trailer. the power lead runs from my battery into a 30 amp breaker and a relay that is only on with the ignition on.
 

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Discussion Starter #8
Thank you all for the tips. I ended up doing the install myself. I spent $165.00 at the farm supply and $83.00 at the local Napa. I used the breakers like everyone suggested also I added a Fuse block. The 2 blue headed screws on the 7 pin are 2-1/2 inchs long and go into the steel cross tube I used spacers between the tube and plastic bumper cover.
Curt #51120 controller
Curt # 57672 plug
Curt #51516 harness adapter





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I have my controller mounted to the fuse cover like Beagle does but i purchased a new one and screwed to that. When I use it, I pull the orig. fluch cover off, plug in the controller and click that cover into place and I'm ready to go. Works very well. When not using the controller plug just push back behind the flush cover.
 
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