Trailer Battery charge while towing?

[MegaRam18]

I have a 2018 Ram 3500 MegaCab DRW. Do I need to add a fuse to charge the 5'er batteries through the 7 pin while towing, or is it already set to go?
There are plenty of videos on YouTube about this with Ford and GM, but not Ram. TIA.

Sent from my old rotary phone using Tapatalk [emoji3513]

 

[turkeybird56]

On the RAM, set to go... At least on the MY 15 I had and the MY 19 I have

Added: Yep, I had to add a fuse to my wife's 2010 F150 to charge, but they did supply it...

 

[crash68]

I know on the 1500s it is the F30(it might be different on the HD trucks) fuse that is for the +12V in the 7 pin trailer plug.
There should be 6 separate fuses for the 4/7 pin plug, they all start with: "Trailer Tow" then a description of what it's for.

 

[Shiva]

Everything you can get at is fused. Starting from the battery back.

 

[Tankerpilot01]

I think the OP is asking if Ram installs the fuse from factory or if one has to put a fuse in later to make that charging wire hot. Valid question as I believe it was on a previous Tahoe I had; the factory didn’t put a fuse in...I didn’t realize it until my battery in my trailer died when I thought it was charging while driving. Then I realized they didn’t make it hot from the factory.



Sent from my iPhone using Tapatalk

 

[wgreggking]

Don't know if there is a fuse, but when I hook up the camper while my vehicle is running, the volt meter I installed in the trailer, reflects the 14 volts/ vs 12.8 on its own un-connected.

 

[MegaRam18]

I think the OP is asking if Ram installs the fuse from factory or if one has to put a fuse in later to make that charging wire hot. Valid question as I believe it was on a previous Tahoe I had; the factory didn’t put a fuse in...I didn’t realize it until my battery in my trailer died when I thought it was charging while driving. Then I realized they didn’t make it hot from the factory.



Sent from my iPhone using Tapatalk

Yes, this

Sent from my old rotary phone using Tapatalk [emoji3513]

 

[NewBlackDak]

It was just there on my 2500. Keep in mind that the wiring is tiny, and doesn’t supply much current.


Sent from my iPhone using Tapatalk

 

[turkeybird56]

^^^^^^^^^^^^^^^^^^ Like I said, already there. Was working from jump street on MY 15 and my current MY 19, just not my wife's 2010 Ford. On my 2014 F150 work truck I had, same setup, Ford gives U an accessory bag with fuse, but really does not document well THAT U need to put that fuse in for system to charge. Do not know on Chevy. . This is for my 1500 truck. I don 't see RAM doing ne thing diff on a 2500/3500. But I will tell U this: If U are tied into truck and are messing with wiring, it DOES NOT TAKE MUCH to pop that fuse, ask me how I know, LOL...

 

[Shiva]

I think the OP is asking if Ram installs the fuse from factory or if one has to put a fuse in later to make that charging wire hot. Valid question as I believe it was on a previous Tahoe I had; the factory didn’t put a fuse in...I didn’t realize it until my battery in my trailer died when I thought it was charging while driving. Then I realized they didn’t make it hot from the factory.



Sent from my iPhone using Tapatalk

I should have read OP better.
This topic got me to grab my crutches and hop out to check My '18 1500 that I tow with regularly.
Found 6 fuses marked trailer. F30 labeled TRAILER TOW has a 30amp square shaped fuse installed.
Prior to this I only trusted it would be live.
If I had a Ford or GM I'd be pissed if I ran a battery dry before I got to a boondock camp.

 

[dhay13]

Good topic. My son has to tow his camper 1600 miles to North Dakota next week and is buying a 2018 2500 6.4 this week to get it there. I had no idea about this and I'm sure he didn't either. Good to know

 

[392DevilDog]

My 12v + does not have power. Signals, lights, brakes work.

I assumed the truck was working (charging), but on our one tow to camp, when we got there battery was drained. Checked for power at 12v + and nothing, key on, key off and running.

Didn't really mess with it, but tonight I changed my 3rd brake light and thought I would see if it was working, before I went to get the light and then after I replaced.

When I first noticed I checked all trailer tow fuses and found one blown...for reverse lights, replaced with hopes it would work for 12v+ also...nope, but reverse light plug works(I just need to add reverse lights to camper lol)

So, I will be checking this out more this weekend, just wanted to know if anyone had any thoughts.

All fuses are good. I will start at the trailer plug connection and begin my search.

Anyone have any advice on how the wire runs or any other connections to check.

Thank you

 

[Gero]

My 12v + does not have power. Signals, lights, brakes work.

I assumed the truck was working (charging), but on our one tow to camp, when we got there battery was drained. Checked for power at 12v + and nothing, key on, key off and running.

Didn't really mess with it, but tonight I changed my 3rd brake light and thought I would see if it was working, before I went to get the light and then after I replaced.

When I first noticed I checked all trailer tow fuses and found one blown...for reverse lights, replaced with hopes it would work for 12v+ also...nope, but reverse light plug works(I just need to add reverse lights to camper lol)

So, I will be checking this out more this weekend, just wanted to know if anyone had any thoughts.

All fuses are good. I will start at the trailer plug connection and begin my search.

Anyone have any advice on how the wire runs or any other connections to check.

Thank you

Check those mcase fuses under the hood. They cubical cartridge fuses. I believe F28, F29 and F30 on the 1500 hemi.

 

[392DevilDog]

Check those mcase fuses under the hood. They cubical cartridge fuses. I believe F28, F29 and F30 on the 1500 hemi.

When I first noticed I checked all trailer tow fuses and found one blown...for reverse lights, replaced with hopes it would work for 12v+ also...nope, but reverse light plug works(I just need to add reverse lights to camper lol)



I already did that.

I do believe the 1500 and 2500 are the same though, it seems 2013 is when they changed up the fuse setup...all I found for info was 2012 and older.

I was hoping there was a second connection that I could go to and hopefully some info on the run of wires. I am guessing they go up the frame rail to the engine compartment.

Thank you.

 

[Gero]

When I first noticed I checked all trailer tow fuses and found one blown...for reverse lights, replaced with hopes it would work for 12v+ also...nope, but reverse light plug works(I just need to add reverse lights to camper lol)



I already did that.

I do believe the 1500 and 2500 are the same though, it seems 2013 is when they changed up the fuse setup...all I found for info was 2012 and older.

I was hoping there was a second connection that I could go to and hopefully some info on the run of wires. I am guessing they go up the frame rail to the engine compartment.

Thank you.

Hmm interesting. Are you checking the charging voltage at the 7pin and not relying on the trailer?

 

[392DevilDog]

Yes, with both a test light and a volt meter.

Using the plug ground and also using a remote ground.

That was how I also found out I had no reverse lights...the center prong...as I do not have reverse lights on camper.

I found many fuses not seated fully. I seated all fuses and tested again.

I then pulled all trailer tow fuses and checked (they are hard to just see if they are blown).

Found the reverse light fuse to be blown. Replaced and center prong has power.

Read somewhere on the interwebs about somehow the 3rd brake light being related.(anything is possible right) Well, it was blown so I replaced it. Still no 12 v+.

I will be honest, I really didn't want to crawl around under the truck. So was hoping for places to check before I had to start checking for a broken wire.

The truck is a 2015 Ram 2500 Crew Cab Longbed 4x4 with the 392 Hemi.

I had also read there may be a second fuse block...but I have been unable to verify that.

Thanks for the help.

 

[Jimmy07]

Yes, with both a test light and a volt meter.

Using the plug ground and also using a remote ground.

That was how I also found out I had no reverse lights...the center prong...as I do not have reverse lights on camper.

I found many fuses not seated fully. I seated all fuses and tested again.

I then pulled all trailer tow fuses and checked (they are hard to just see if they are blown).

Found the reverse light fuse to be blown. Replaced and center prong has power.

Read somewhere on the interwebs about somehow the 3rd brake light being related.(anything is possible right) Well, it was blown so I replaced it. Still no 12 v+.

I will be honest, I really didn't want to crawl around under the truck. So was hoping for places to check before I had to start checking for a broken wire.

The truck is a 2015 Ram 2500 Crew Cab Longbed 4x4 with the 392 Hemi.

I had also read there may be a second fuse block...but I have been unable to verify that.

Thanks for the help.

Check the harness where it runs on the frame. There’s a pinch point near the rear suspension.

 

[392DevilDog]

F28 trailer tow b/u
F29 trailer tow park
F30 trailer tow
F53 trailer tow Lt turn/stop
F81 trailer tow rt turn/stop


These are the fuses I checked, F28 being the one I changed.

I believe it should have power at all times, off, accessorie, and running?

 

[Jimmy07]

F28 trailer tow b/u
F29 trailer tow park
F30 trailer tow
F53 trailer tow Lt turn/stop
F81 trailer tow rt turn/stop


These are the fuses I checked, F28 being the one I changed.

I believe it should have power at all times, off, accessorie, and running?

Yes, the battery pin on the 7 way connector should always be hot. It goes directly to the battery via a 30 amp fuse at the F30 location in the fuse box. None of the other trailer plug fuses (or any other circuit on the truck for that matter) has anything to do with the battery circuit on the 7 way connector.

 

[392DevilDog]

Looks like I will be getting familiar with the wire then.

Thank you