Wiring Needed to Flat Tow a 2016 Jeep Wrangler

Published 09/09/2016

Products Featured in This Question

Pollak Circuit Breaker - Cycling/Automatic Reset - 40 Amp - Straight Mount Bracket

(49)

$8.02

Blue Ox Avail Non-Binding Tow Bar - RV Mount - 2" Hitch - 10,000 lbs

(769)

$858.72

7-Way Molded Trailer Wire Connector, 4' Long

(381)

$37.94

7-Way Molded Trailer Wire Connector, 6' Long

(394)

$44.94

Roadmaster 7-Wire to 6-Wire Flexo-Coil Kit

(253)

$100.93

Roadmaster Battery Charge Line Kit for Towed Vehicles

(1236)

$42.89

Roadmaster Brake-Lite Relay Kit for Towed Vehicles

(713)

$48.00

12 Volt Outlet Kit, 20 amps

(343)

$36.44

Question:

I have a 2016 Jeep Wrangler that I am wiring to be used as a towed vehicle behind my class C Motor Home. I will be installing a Blue Ox Patriot portable breaking system on the Jeep, this will require a 12 volt draw from the Jeep battery via a cigarette lighter plug. My motor home is wired with a 7 way plug. I will be wiring my Jeep lights using a Demco 9523129 harness with 4 way end. I purchased the etrailer H20043 wire harness and A7WCB plug to connect from the RV to the Jeep. I will be providing a constant 12volt from the RV to the Jeep battery. I also purchased the PK54540 to place in line of the constant 12 volt supply to the battery but as I look at it I am not sure that is what I want. What should I add in line for the 12 volt supply to avoid over charging the Jeep battery while the RV is feeding this supply? I will be using a converting 7 way plug to 4 way plug with 10 gauge 12 volt supply available

asked by: Albert H

Expert Reply:

It sounds like you've created your own umbilical to go from the 7-way on your RV to a 7-way on your Jeep. The Hopkins connector # H20043 is 4 feet long, which isn't going to be long enough to bridge the gap of space for flat towing. You're going to need at least 6 foot umbilical. For a 6 foot 7-way molded cable use # H20044. We typically don't see 7-ways on the front of vehicles, for a great 7-way to 6-way umbilical with a 6-way (which is most common) connecter and mounting bracket I recommend # RM-146-7.

Since you have the Demco flat towing 4-way harness, you'll use that to connect to the 7-way umbilical you've made (or 6-way). In order to plug your 4-way Demco harness into the 7-way umbilical you will need a 7-way trailer connector socket # HM48480 with open pins. You'll need to cut off the 4-pin connector of the harness, if it has one, and wire it to the 7-way socket. Now you can plug your umbilical adapter from your RV into your Jeep.

From the 7-way (or 6-way) socket in the front of the Wrangler you will need to install the Roadmaster Battery Charge Line # RM-156-25 and connect it to the Jeep's battery. I spoke with our installer, and he said you can use the 40 amp circuit breaker in place of the included 15 amp, however it isn't needed because the charge kit includes a 15 amp circuit breaker. The 15 amp will be plenty, when you use a higher rated amp like the 40 amp you could end up damaging wiring if it's temperature rating is not high enough which will fry the wiring. The chargeline kit is designed to handle the 40 amp breaker as well as the included 15 amp one.

If the Jeep does not have a 12 volt connector that runs with the vehicle turned off or if the Patriot doesn't have a long enough cable to reach it you will need the 12 volt outlet kit # RM-9332. This will need to be plugged directly into a 20 amp fuse and your battery. This kit has a built in 20 amp circuit breaker which would eliminate the need for the 40 amp breaker to be used inline for this connection.

Our installer also suggested a Brake Light relay # RM-88400. This is something you won't know you need until you hook everything up and test it. So it's good to have it ahead of time instead of after you find out you need it.

If you don't already have them you're also going to need a tow bar like the Blue Ox Avail # BX7420 which comes with the safety cables. You'll also need the base plates that are specific to your Jeep, see attached link. And possibly a high/low adapter. See the help article I've attached to this page.