What is the Difference Between a 4-Way and 7-Way Trailer Connector


What is difference between a 4 pin and 7 pin trailer connector?


Expert Reply:

A 4-Way trailer connector has the basic lighting functions only; running lights, left turn signal and brake lights, right turn signal and brake lights, and ground.

A 7-Way has these functions and a 12 volt circuit, a circuit for electric trailer brakes (requires a brake controller in the vehicle), and a reverse light or auxiliary power circuit.

There are other types of connectors as well. I have included a link to our help article that shows and explains the various connector types.

expert reply by:
Michael H

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Follow up Questions

Jim K.

My 2019 Minnie Winne has a 7 pin connector in rear for flat towing. What wiring harness/connector do I need for my 2018 Wrangler Unlimited? I want to get the patriot II, can I keep it plugged in recharging while driving, through the RV connections or do I need to install a 12v hot wire for the Patriot II? 98710

Reply from Jon G.

Here are some shopper's guides we put together for Jeep owner's that breaks down everything that you need whether you have the JK or the JL. 73495


any plug and play harnesses )round 7)for a 2015 Chrysler Town & Country dad mobile, have a pop up for it 97081

Reply from Chris R.

For your Town & Country you can use the Tekonsha T-One # 22121 , which includes everything needed to install a fully functional 7-way connector. 71118

Darin F.

I just bought a 2019 Ford Ranger Lariate w/ tow package in March. Ive towed my camper twice; it seems the trickle charger from the 7 pin is not working (so the mini fridge in the camper wont run to keep things cool while traveling.) If the tow package missing this feature, or is there something I have to turn on? 96991

Reply from Chris R.

The 2019 Ford Ranger should have that 12V circuit activated as part of the tow package, but it's a little odd in how you actually get it to send power. I linked a separate answer page below that does a nice job of explaining this. 71117

Reply from Audrey

@DarinF — Unless you have a residential fridge with an inverter your tow vehicle will have virtually no affect on whether your fridge will run. Your fridge can run in one of two conditions: 12V AND propane, OR shore power. If you have only 12V power available (such as when towing), your fridge needs propane to stay cold; the 12V runs the circuitry, burning propane cools the unit, and the TV charge on the battery should be able to keep up with that demand. The cooling process of the fridge does not run directly on 12V. Even if your battery is not being charged by your tow vehicle, assuming a healthy battery, your fridge should run on propane for long enough for a day on the road with just the charge on the battery. But there are A LOT of factors that work into that. The decision whether to run the fridge on propane while traveling has been widely covered here and elsewhere, so that decision is up to you. Personally, I run mine on propane in transit and always have. My fridge runs "end to end", meaning I keep it plugged into shore power at the house, run it on propane (or generator) in transit, and shore power/generator while camping. Same for the ride home. I don't turn it off until I have all the food out at the conclusion of a journey. If you don’t want to run the propane while in transit your food should still stay cold. Just make sure your fridge has had long enough to become cold and the food you added is cold as well. If you still can’t travel at least 8 hours without your food getting warm then you have something wrong with the fridge like maybe the seal leaking. Also keep in mind that some very new campers are made to automatically switch off the LP when the camper senses motion. 75438

Pat D.

no power to trailer; 5 pin, powered by 2013 Nissan frontier 96901

Reply from Chris R.

Are you not getting any power at all on the connector or is it just a certain function that's not working (trailer running lights or brake/turn signals)? Can you tell me what model trailer harness is installed on the Frontier (or if it's a factory unit)? 71116

Boris G.

for a ford transit 250 which is what I need to install to connect a trailer with 2 axles with brakes, and where I could make an appointment to do the work with you. Thank you 95702

Reply from Chris R.

I can definitely get you set up with the correct parts to add to your Transit 250. Just to be sure I recommend the right components, can you tell me what model year the vehicle is? 70529

Reply from Boris G.

It is a ford transit 250 of the 2018 Medium, remember that if you can give me any address where I could get your services. Thank you 70550

Reply from Chris R.

Thanks for the info! Starting with the hitch, the Curt Class IV # C14012 will work really well. Then for wiring I recommend the Tekonsha # 22114 , which includes everything needed to install a fully-functional 7-Way connector. The kit also includes wiring to install a brake controller (which is needed for your trailer) like the excellent Tekonsha Prodigy P2 # 90885 . We are located in Wentzville, MO so if you're nearby we can definitely set up an install - just give our Customer Service team a call at 800-298-8924 and they can help you out with this. 71115

Joel M.

Have Titan xd 2016 pro 4x has factory 7 way and 4prong wold like to get 7 way on a old car hauling trailer. Backup lights, brakes. Do you have plug ready for trailer, need to re wire and light whole trailer, and brain transplant for myself. Can you help me please? Thanks 77900

Reply from Chris R.

Unfortunately I can't help with the brain transplant (I'm on a waiting list myself) but I can with everything else! To wire your trailer up with a 7-Way connector, I highly recommend using the etrailer 7-Way Upgrade Kit # e99011 . This allows you to make this conversion and keep all your connections clean. For extra wiring you can use 12 gauge # 12-1-1 for the brakes and 12V circuit and 16 gauge # 16-4B-1 for the lights, both of which are sold by the foot. It sounds like you're also wanting to add or replace some light assemblies as well - I've linked our full selection below if that's the case. I also linked a handy wiring article that you might find helpful. 63274

William W.

Is there an adapter available to go from a 7 pin wire connector on a 2014 ford truck F350 to a trailer plug which is a 9 pin? And if not whats different from a 7 way versus a 9 way? Thank You, 77722

Reply from Chris R.

There isn't a clean adapter available that goes from a 7-Way to a 9-pin connector, but we do have still have solution. I've linked an informative answer page below that details the parts you will need. 63273

Danielle D.

So I have a camper with a 7 round and a vehicle with a 4 flat pin. Can I just buy an adapter or will I not be able to use the brakes on the camper, only the lights? 76473

Reply from Chris R.

If you were to just hook up an adapter like the Tow Ready # 30717 (without running those additional wires) you would only be able to activate/power the signal lights on your trailer. If the trailer has electric brakes a better option is the Wiring Kit # ETBC7 , which includes all the additional wiring needed to activate the rest of the circuits. You'll also need to add a brake controller like the Prodigy P2 # 90885 to your tow vehicle (if you haven't already). 62406

Dennis L.

Can I get a plug and play trailer wiring kit that requires no cutting of wires to go with hitch from you for 2001 freightliner MT45 former snap on truck going to be used as off grid rv? 76026

Reply from Chris R.

There isn't a custom plug-and-play harness available for your 2001 Freightliner MT45 (I really wish there was!). You'll need to go with a hardwire kit like the excellent Tekonsha # 119190KIT for the 4-Way connector. If you need a fully functional 7-Way, you'll then use the Wiring Kit # ETBC7 , which includes everything needed to convert the 4-Way to a 7-Way connector. 62129

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