Trailer battery not charging error, help

[Syberspace]

I have searched this site and the F150Gen14 site. Over there, there have been several discussions on this, but I can not find my solution.

When I plug in the 7 pin to my truck, and start my truck, I get a trailer battery not charging error on the screen. The trailer has brakes and this is the emergency brake battery.
My trailer battery is good... 12.98 volts.
I can see 12.98 volts at the 7 pin on the trailer.

Not sure this is related, but also, my trailer interior lights (this is an enclosed trailer) will not come on. However, If I start the truck and unplug a replug in the 7 pin, they work. I checked the battery both ways as well... before and after I unplugged and replugged the 7 pin to get the interior lights to come on. No charging either way.
I tried all the other Gen14 recommendations... start the truck, close the doors, leave keys in the cab, put in drive or reverse and the trailer lights will not come on unless in unplug and replug the 7 pin. Pulling my hair out!

The external light work fine.

Any ideas?

Thanks.

 

[hammer_68]

I've also just noticed my '18 Raptor is not charging my trailer battery. My '14 F-150 did just fine so I can't figure out why a newer truck that recognizes the trailer won't purposely charge the battery

 

[Syberspace]

The F150 forum suggested checking the grounding on the trailer... going to do that the next chance I get and will update.

 

[hammer_68]

The F150 forum suggested checking the grounding on the trailer... going to do that the next chance I get and will update.

If it wasn't grounded the lights wouldn't work. Everything else on mine works, just can't figure out why the Raptor isn't charging the battery. Maybe the 7-Pin connector has a bad connector/wire?

 

[Syberspace]

If it wasn't grounded the lights wouldn't work. Everything else on mine works, just can't figure out why the Raptor isn't charging the battery. Maybe the 7-Pin connector has a bad connector/wire?

Good point... But why when I unplug and replug the interior lights will work... every time. Just no charging of the battery. Plus, I can see the 12 volts on the trailer side on the trailer plug. I am going to look at the wiring this weekend. The trailer is at my cabin.

 

[hammer_68]

Good point... But why when I unplug and replug the interior lights will work... every time. Just no charging of the battery. Plus, I can see the 12 volts on the trailer side on the trailer plug. I am going to look at the wiring this weekend. The trailer is at my cabin.

any updates?

 

[Syberspace]

Just figured it out. Damn 7 pin plug on the trailer side is bad.
I get 8.5 volts at the plug and I have 13.2 in the trailer. I thought it had something to do with the LED lighting, as it’s on the same circuit.
I finally checked resistance from inside the trailer to the plug connection. 6M ohms. I cut the insulation just before the plug and I’m around 0.5 ohms.
New trailer too. SMH.

 

[Syberspace]

Just figured it out. Damn 7 pin plug on the trailer side is bad.
I get 8.5 volts at the plug and I have 13.2 in the trailer. I thought it had something to do with the LED lighting, as it’s on the same circuit.
I finally checked resistance from inside the trailer to the plug connection. 6M ohms. I cut the insulation just before the plug and I’m around 0.5 ohms.
New trailer too. SMH.

After replacing the seven pin plug on the trailer, I still had the same problem. The battery would not charge. Ended up pulling the battery charger that was part of the breakaway kit. It was basically a three wire solid-state device with two positive leads and one that went to the breakaway switch. Everything is fine now.
Not sure why the need for the little solid-state battery charger device. When you’re hooked to the truck, your truck charges the battery.

 

[hammer_68]

Huh, that's interesting. My trailer is old enough it's just wires. I think my problem was a blown fuse, #24 or #25