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Has anyone heard of any problems with late model Ford trucks not sending power back through the trailer hitch’s seven-pin connector to charge the truck camper’s house battery? I’m pretty sure it isn’t my Truck Camper, but is something in the logic Ford uses to decide to send current back to charge trailer or TC house batteries.
Here is some geeky technical trouble-shooting background:
-We got a new 2017 Ford F350 for our older truck camper. According to the Victron battery monitor, our old Tundra could get about 1- 2 amps back to the TC house battery. Our new Ford couldn’t get any current from day one.
-I’m pretty sure the problem isn’t with the TC. I started trouble shooting the TC wiring, and determined that the TC’s house batteries voltage could be measured from the TC’s pigtail connecter when it was unplugged from the trailer hitch’s 7-pin connector. The voltage was within 0.05 volts of the battery voltage measured at the battery posts and by the Victron battery monitor. So, I’m pretty sure my TC 12 volt charging wiring is fine from the trailer hitch to the battery.
-Then I checked for a voltage on trailer hitch 7-pin connecters’ 1 and 7 o’clock positions (as well as all the others). There was no voltage detected for battery charging but all the running lights etc. worked fine. Then I checked the fuse for the trailer-charging relay and found it missing so replaced it. There was still no current going back to the pigtail.
-I took the truck and camper to the dealer. It turns out, not only was the fuse missing, but also the relay and its wiring harness and socket for trailer charging. They ordered to parts and were about to replace them when they contacted Ford again and found out the design was changed, but not yet recorded in the tech manuals. Ford now has a new circuit system that won’t close the relay to send current back to the 7-pin connecter unless the pigtail is plugged in and “detected”. My truck was assembled in July of 2017 and we bought it in December.
-But when my pig tail is plugged in, it won’t trigger the logic to send current back to the 7-pin connecter. Nor does the truck’s integrated brake controller recognize that there is something plugged into the trailer hitch 7-pin connector.
Yup, I know exactly what the problem is. Ford. Don’t get me wrong; I absolutely LOVE my 2017 F350. But if you didn’t order the camper package or some other obscure thing, then the circuitry to charge the camper/trailer batteries is not there and you cannot add it the way it should be done. I ordered my truck. I got the fancy tow package, the gooseneck/5er prep package, the trailer camera/TPMS and everything else I could think of. But my truck doesn’t have the relay and fuse needed to power the battery through the trailer plug. And the sockets aren’t even wired or pinned to add it.
So you will have to come up with your own fuse and circuit and wire it into the plug on the bumper and/or in the bed. Really ticked me off.
I’m running a #4 cable from one of the front batteries to my camper and another one for a ground to the frame. I put a fuse on the battery and then a 75amp solenoid so I can cut it off while stopped. In fact, I’m controlling the solenoid with one of my up-fitter switches which goes off when I shut the power off to the truck. That way I don’t forget and let the camper (Cirrus 820) run my starting batteries dead.This issue comes up often and even if you have an earlier model, the charge lead amperage output is pretty limited ( put an amp meter in line to check it with the camper tethered) so lots of folks resort to running the 4 ga from the battery, if charging the camper battery is really essential. A good solar system makes running the truck to charge the battery less urgent. Overall there is no ideal charging off the truck as at best you are stuck with charging dissimilar battery types and sizes.
Steve and Andra
2012 F350 6.2 gasser SRW LB
Fab Fours front and rear in case we run into a rhino
2019 Northstar Laredo SCDirk, You have the exact same problem and convinced me it is a stupid Ford design issue! I’m going to try the dealer one more time since they already got the relay, sockets and wiring harness.
I didn’t see the missing connectors for the fuse and relay, but the dealer did and ordered the parts. Then they decided to check with Ford one more time before installing and Ford convinced them the problem was with the camper even though we know it isn’t. I’m sure Ford had no idea of all the complexities associated with two different options: camper package and towing package. Also, I’m not sure the camper package would help since I charge through the 7-pin connecter. And if my memory is right, the camper option has a separate connecter for the camper.
When we laid out all the features we wanted in the truck to the dealer they ensured us there would be no problem with a truck camper charging through the pig tail, especially with the heavy duty alternator our track has. I didn’t think the camper package option would have been required along with the tow package! Since it took them several weeks to find a truck with the options we wanted, adding the camper package option would have made the search even harder. Some how we need to get this out to the truck camper community for awareness and maybe to Ford so they fix a stupid design flaw.
Maybe this can be useful information.
I am also looking for a wiring jumper modification that I saw reference to in 2017.
It referred to installing this jumper in the wiring, I think, under the dash.https://ford.oemdtc.com/2482/trailer-charging-system-operation-2017-ford-f-super-duty
Bill and Kira Jones
2018 Northern Lite 9-6Q SE
2017 Ford F350 6.2L gasoline, SRW, CC, LB, 4X4, 4.30 DIFFHere is some “gospel” from Ford about the subject.
Still looking for that jumper information.Click to access Q-263_Trailer_Tow_02212017.pdf
Bill and Kira Jones
2018 Northern Lite 9-6Q SE
2017 Ford F350 6.2L gasoline, SRW, CC, LB, 4X4, 4.30 DIFFI want to thank everybody for their input and advice. I feel pretty confident I have found the source of my issue – it’s a Ford poor design choice in the trailer battery charging circuit. Ford’s design assumes you only want to charge a trailer battery if there is an electric brake connected. TC don’t usually have an electric brake. There are 3 ways around this.
By bypassing the trailer battery charging relay (see https://www.putco.com/pub/media/productattachments/3274/92009I.pdf) you can have a direct connection from the truck’s charging system to the TC battery. When I tried this, it worked and sent 3-4 amps back to my TC battery. BUT, without a switch to turn it off, it would also send power from the TC battery to the Truck when the truck was off. So, I will either add a solenoid or only use it in emergencies.
So I tried another experiment. By adding a 6-ohm resistive load to the brake controller pin to ground on the 7 pin connector, my truck detects that a trailer is attached and sends a charge current to the battery. I’m most likely going to permanently wire this in so the truck “senses” that there is an electric brake connected. Since resistive loads get hot, care must be taken to ensure the resistive load is isolated from anything that can ignite.
Finally, wire a separate heavy gauge wire from the alternator, through a solenoid that closes a relay when the truck is on. Truck Camper Adventurer has an article on this.
I’m probably going to do the resistive load.
I believe this problem is older than just the later models. I have a 2012 F350, and also see very limited current that charges the TC batteries. Even after an all day drive (8 hrs), the charge is very limited.
I’ve heard of ‘smart’ alternator design by Ford that makes this limited charge a ‘feature’.
I do believe that the 4 gauge wiring/solenoid/fuse setup will bypass the poor design, but be aware of warranty issues that Ford could evoke.
Also be aware that any additional options like towing packages, MAY require an updated Basic Computer Module (BCM), which isn’t cheap. And you’ll need new keys to go along with the BCM, which also aren’t cheap. Off subject, but I had to have a BCM changed, because the right rear turn signal didn’t work – $650.
I’ve gone with the solar solution that makes this problem less of an issue. Love the F350, and there’s a reason there are tons of them out there.
Good info in the forum, as usual.
2012 F350, 6.7L SRW
2015 Alaskan 8.5 CaboverI agree that installing a separate high amperage charging system would be the best solution. The electronics on new trucks is nice but, when you have issues with them I wish I still had an old Ford or Chevy with no computer.
2007 Dodge 3500 Dually 4x4
Cummins 5.9, 6sp, PAC
brake, Big Wig, Timbrens
2000 Lance 1130
2004 Jeep RubiconI too have a non-charging TC battery but the thing that caught my eye was that the OP had a Toyota Tundra which is what I have (2016). Our new Lance 650 house battery doesn’t charge. The dealer measured the voltage at the house battery with the truck running and said voltage was good. I don’t know enough about it to argue with them but in this thread are comments about measuring amps, not volts. And what I DO know of electricity amps is what we’re talking about, hence the huge (#4) wire. So I guess my question is if you (OP) had a Toyota Tundra that was successfully charging your camper why doesn’t mine?
Here is one more fly for the ointment: the Lance 650’s pigtail comes out the front of the camper and the truck’s recepticle is on the rear bumper. An extension pigtail had to be made up to reach. So now the wire comes from the alternator some 19 feet to the back bumper then 6.5 feet + slack to the camper then another four across to the battery on the right side of the camper. We’re talking about roughly 30 feet of #6 wire! Could that be where the problem lies?
The dealer measured the voltage at the house battery with the truck running and said voltage was good. I don’t know enough about it to argue with them
A little background information for you: A 12 volt battery consists of 6 cells, each of which is approximately 2.1 volts. So a fully charged 12 volt battery will actually read 12.6 to 12.7 volts when fully charged. In order to charge a battery, the system must deliver a higher voltage than that. So when the truck is not running, the house battery should measure 12 to 12.7 volts. When the truck IS running, if it’s charging the house battery, you should read 13 to 15 volts, with 14.4 to 14.6 being more or less the ideal range for a battery. If, with the truck running, you are only reading 12 to 12.7 volts, the truck is NOT charging the battery. A simple meter from Harbor Freight ($5 -$10) is all you need to check this.
You can measure your engine starting battery both with and without the truck running to see what I mean and to see what your charging voltage actually is.
As for your long charging wire, too long a run of too thin a wire causes a voltage drop, which leads to less amps flowing and means it takes longer to charge the battery.
Hope this background info helps.
Regards
John
I don't like to make plans. They cause the word "PREMEDITATED" to get used in court!
DON'T FEED THE VULTURES!
My Body is a Temple! Ancient, Crumbling, Probably Cursed . . .Dave, if your F350 has the upfitter switches perhaps you can use one of them to toggle the charging circuit.
we will be custom ordering a 2020 F350 so we can pick any set of options….
reading the thread above I’m sad that it may well not be a simple plug in for our new pop up camper …. :-/
a question about the upfitter switches… where does one tie into them? in other words – where do any wires need to be run, to use the switches with those wires?
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