No Power to Hitch 7-Way Power Outlet

[bigrollingturd]

Hi! First post here. I have a 2018 FR3 32DS. We purchased used, so I don't have the full manual or fuse layout.


Just wired up my tow vehicle and plugged it into the FR3 - no power. Tested brakes, blinkers, lights - nothing.


Also ran some voltage tests at the outlet itself and nothing coming through, so I know it's not my jeep.


Thanks for any help or diagrams; not sure where to order the fuses either.

[bigrollingturd]

I checked my VIN and did some more digging. Verified I have a 2018 Ford F-53 Chassis. I found the Ford Fuse diagrams on pages 69-88 of this document.

Anyone have experience with: 1) identifying the exact locations of these fuse boxes, 2) buying these fuses, and 3) replacing them and/or fixing this issue?

[Bama Rambler]

As for the exact location of the fuse boxes, I don't know, but they should be easy to find.
I also noticed that on several of the boxes they tell you exactly where it's located.

The fuses can be found at any auto parts store. If you look on the legends they designate the type of fuse they are if they're not standard fuses.

[ScottBrownstein]

There may be a junction box under the coach that feeds the 7 way. Perhaps it was never connected?

[2dogs]

If you are only plugged in and not fully connected to the trailer itself, you will have no ground.

[bubbles]

Originally Posted by 2dogs

If you are only plugged in and not fully connected to the trailer itself, you will have no ground.

It's a motorhome and Jeep.

[OHIOFR3]

Originally Posted by bubbles

It's a motorhome and Jeep.

Are you connecting the 7 spade RV to a 6 spade receptacle on the Jeep? If so, orientation may be off. Have you tested the RV spades with a 12 volt test light? Start at the RV plug and work backwards through the system until you find power. Those are my only suggestions.

[perrogie]

The motor home has a power distribution box under the hood with fuses and relays under the cover. There is also a fuse box under the dash close to the brake pedal. The motor home has separate fuses feeding the trailer connector at the back and may also have relays. I have seen situations where the fuses and/or relays were not installed at the factory. Hope this helps

[rk06382]

Originally Posted by bigrollingturd

I checked my VIN and did some more digging. Verified I have a 2018 Ford F-53 Chassis. I found the Ford Fuse diagrams on pages 69-88 of this document.

Anyone have experience with: 1) identifying the exact locations of these fuse boxes, 2) buying these fuses, and 3) replacing them and/or fixing this issue?

Did you check the Battery compartment?

FR3 Battery Control Center Schematic 5-31-16 117963A.pdf

FR3 Battery Control Center Schematic 5-31-16 11796.pdf extract:

[ScottBrownstein]

Originally Posted by rk06382

Did you check the Battery compartment?

Attachment 263517

FR3 Battery Control Center Schematic 5-31-16 11796.pdf extract:
Attachment 263516

Good find, but that would only affect the charge line in the 7-way. The brake, turn and running lights are sourced from the F-53 chassis wiring.

Here is a link to the F-53 stripped chassis fuses. Notice the relays and fuses for trailer lights https://fuse-box.info/ford/ford-f-53...uses-and-relay

[bigrollingturd]

Yes, I believe it's a 6 spade on Jeep to 7 spade on RV.

The wiring harness kit was made by Cool Tech and this is the one I bought for the 2021 Jeep Wrangler JL:

https://www.cooltechllc.com/2018-jee...rness-kit.html


I tested the RV 7 spade at each metal piece and center with a 12V and had no signal, even when running blinkers, etc. on RV.


I am starting the fuse work this week and I'll let you know how it goes.

Originally Posted by OHIOFR3

Are you connecting the 7 spade RV to a 6 spade receptacle on the Jeep? If so, orientation may be off. Have you tested the RV spades with a 12 volt test light? Start at the RV plug and work backwards through the system until you find power. Those are my only suggestions.

[bigrollingturd]

Originally Posted by ScottBrownstein

There may be a junction box under the coach that feeds the 7 way. Perhaps it was never connected?

I tried to find that! No dice.

[bigrollingturd]

Originally Posted by OHIOFR3

Are you connecting the 7 spade RV to a 6 spade receptacle on the Jeep? If so, orientation may be off. Have you tested the RV spades with a 12 volt test light? Start at the RV plug and work backwards through the system until you find power. Those are my only suggestions.

Yes, 6 to 7. I used Cool Tech's Jeep JL 2021 harness kit. All 12v testing on Jeep worked great. No current discovered during 12v testing on FR3 hitch receiver when running lights and blinkers. The harness kit came with a 7 spade plug that only goes in one-way into the RV receiver.
Cool Tech's tow harness here: https://www.cooltechllc.com/2018-jee...rness-kit.html

[Grumpy7159]

Get a 7-pin tester to find the problem in the RV or the Jeep. My Ford doesn't have power on the plug until I have a trailer (or tester) properly connected. I found a electronic box on the chassis that is used for trailer lights. It even tells me my trailer is connected, how much current is drawn by the electric brakes, etc. 7-pin tester works in chasing down problems.

[bigrollingturd]

Ok got myself a 7 pin tester for 11.99 at a local RV store and the tow outlet was working fine on the FR3. No fuse replacements needed for now!

Jeep lights still not working but figured out the wiring on the 6 pin connector was wrong. I matched the colors one for one, but color matching didn’t matter. Apparently the 6 pin has to have the 12v in one spot, ground at another, etc. Once rewired with the Cooltech diagram, the colors didn’t match up with the 6-7 pin wire going between Jeep and RV but everything worked great!

Thanks everyone.