Wiring a 5 flat harness

Halibut214

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I have a 2018 Wrangler Unlimited JL that I'm trying to wire the 5 flat adapter (I have the Curt 4 flat) so I don't have to get out and put the brake clip in every time I back up. Hoping someone has done this and can tell me where they tied in to the wiring and if there was enough power in the wire to activate the solenoid or if you had to wire through the battery? Thanks
 

Starcraft5834

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yes, I have done it, the 5th wire goes to reverse light.. web search your vehicle, you should be able to identify the color,, or put a tester on it when someone puts it in reverse... splice it in there...
 

alldodge

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Always good to tells us old folks everything your working on so we don't have to guess

I'm assuming you have disc brakes and the solenoid you referenced is placed inline with master cylinder.

If you connect the solenoid to the backup lights, this will energize the solenoid.

Edit: looks like star has ya covered
 

Halibut214

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My apologies if I didn't make it clear but I understand I need to go to the back up lights and yes you assume correctly alldodge. I don't want to screw up something in my Jeep and I've heard, though not confirmed, on the newer Jeeps there isn't enough power to activate the solenoid by wiring directly to the backup lights. Yes, I could try it and find out but again, don't want to risk my Jeep.Was hoping someone had done this and could tell me. Thanks
 

alldodge

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OK, I added a lighted switch on the dash which sends power back to energize mine. Flip the switch before I start to stop at the ramp and all good.

Hope someone with a Jeep comes in and answers your question
 

Halibut214

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If it may help anyone else I decided to go for it and wired it up. I removed the driver side taillight and connected into the Orange wire on my back up lights. I didn't fry anything and have power at that terminal in reverse so fingers crossed. I'm taking the boat out tomorrow so we'll see it there's enough power there to engage the solenoid on the brakes.
 

Scott Danforth

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I got lucky, I simply bought a 7 pin to 5 pin adapter for the truck.

however on the prior S-10 blazer, the blue wire gets wired to the reverse lights. not knowing the current draw, i added a relay and a 10 gauge wire up to the battery with an in-line fuse. the reverse lights fired the relay, the contacts closed the circuit between the battery and the 5th pin.
 

JaseBosto

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I would just run a separate switched wire straight from the battery with a fuse, since you are concerned that the Jeep reverse lights dont have the grunt for it.
 

jimmbo

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If you were worried about the Current Draw of the Solenoid, you could have wired a Relay into the Backup Light Circuit and then used the Relay to send Power directly from the Battery to the Solenoid
 

GA_Boater

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I don't want to screw up something in my Jeep and I've heard, though not confirmed, on the newer Jeeps there isn't enough power to activate the solenoid by wiring directly to the backup lights. Yes, I could try it and find out but again, don't want to risk my Jeep.Was hoping someone had done this and could tell me. Thanks

Doesn't your Jeep use LEDs in the backup lights? That could be why you've heard it doesn't have enough power for the solenoid. Nothing is simple on newer vehicles.

Your Jeep uses a CANBUS for everything and the CANBUS signal is connected to a driver for all the lights. And LEDs don't use 12volts in new vehicles. Install a relay and switch and call it done.
 
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Leardriver

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The switched wire works. Just don't forget to switch it off, or you won't have trailer brakes. I knew a guy who wired his blue wire to his brown wire, the taillights. Then, he turned his taillights on when he was backing. That works, but...What if you drive at night? You won't have brakes if the taillights are on. He said he never towed at night. Hmmm.
However you reliably get 12 volts to the blue wire is a solution, it just isn't too difficult to tap into the back up light wire.
 
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