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Oasisbob's avatar
Oasisbob
Explorer
Jun 26, 2021

EVER HOT TERMINAL?

First long trip with our new to us 2018 Ford Explorer with factory tow package. I easily installed my Prodigy brake controller. On our first long trip we noticed trailer batteries are not charging while we drive. There is no power on the ever hot terminal on the Explorer. Is there a fuse that needs to be installed? Any clue where it is located and size? Car did not come with a owners book. Thanks much
  • There should be a fuse and a relay in the under hood fuse panel. Relay is so trailer does not drain TV battery when engine is not running.
  • 7 pin is pretty worthless for charging battery anyways, conductor is too small. If you want to actually put some juice in the battery add a dedicated charge cable. There's plenty of info on different ways to do this out there, but the involve either bigger cables, converting to AC and then back to DC, or upping the DC voltage and stepping it back down. You also have to consider load on the alternator and how to limit it or add an additional alternator dedicated to charging.
  • I just searched Google for "2018 ford explorer owners manual" and came up with it on the first try.

    https://owner.ford.com/tools/account/how-tos/owner-manuals.html?year=2018&make=Ford&model=Explorer

    Probably need the relay/fuse for the charge wire.

    How do you know it's not charging? It won't show much more than maybe 13.5 volts when it's 'charging' anyway.

    Good luck! Mitch
  • Ford ships their trucks with the relay in a little baggie in the glove box. You just have to plug it into the fuse box under the hood, in the circuit labelled trailer charging in the owners manual.
  • Look into DC/DC battery charging. I use a generator with a WildKat converter, but if I had to charge batteries off the tow vehicle I would run dedicated cables to the rear and use a DC/DC charger connected directly to the RV batteries. I've used the Blue Seas stuff in the past. You won't ever get enough juice from a 7 pin connector terminal to restore a full charge. Thats mainly a power source for the tiny emergency brake batteries on utility, car hauler or whatever trailers. Its not hard to set up DC/DC charges, not really expensive either. But a solar charging system may be a better choice in the long run.
  • dockmasterdave wrote:
    Ford ships their trucks with the relay in a little baggie in the glove box. You just have to plug it into the fuse box under the hood, in the circuit labelled trailer charging in the owners manual.


    Ford does not always ship their trucks with the charge fuse/relay not installed.

    I have owned a 97, 2003, 2006, 2013, 2019 and now a 2020 Ford truck, all of those shipped with the charge fuse and relay factory installed..

    Now GM, that is a whole nuther thing..
  • Thanks to the link posted I found the correct fuse and it was installed and good. I will put a volt meter on the TV plug in the morning and see what I have. May be a trailer problem. Many thanks to ya all
  • Did you find the receptacle for the relay? Is it installed?
    Power to the trailer connector only hot when engine is running.
  • Oasisbob wrote:
    Thanks to the link posted I found the correct fuse and it was installed and good. I will put a volt meter on the TV plug in the morning and see what I have. May be a trailer problem. Many thanks to ya all


    You have a 2018 Ford, the newer Ford vehicles with factory towing are setup with a "smart towing module". All trailer towing functions like stop, turn, marker, brake control and charging go through this module.

    Sticking a meter into the socket will read zero volts (or near zero)unless the trailer has been connected, engine started AND you must press and hold the brake pedal for 30 seconds or a bit more.

    My 2019 and 2020 Ford trucks use this smart towing module, 2018 may use it as I am not sure exactly what yr they started this setup, our 2013 did not have that module. I would recommend you look up the trailer section in the manual on how yours works..
  • Some vehicles won’t charge until you close the door and start driving. Testing while parked may not work.

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