Charging while towing

[Gonefishin]

I've read most everything here, but I have a wierd problem. I have the trailer tow relay installed in my TV ('08 F-150), and the 12-volt charge pin on my 7-pin connector is HOT! That is, it lights up a test light when the TV is running. All lights are working properly on the trailer too.

But, I'm still not getting any charge to the tongue-mounted battery, which is wired into the 7-prong plug with a simple in-line fuse. No converters or anything like that. Just two wires, from battery to the plug, which plugs into the vehicle's receptor. And the receptor plug on the vehicle is "hot, each one including the "12-volt charge" pin.

That means the wire from battery to the plug? But that's brand new and clean enough to eat with. Ground on trailer is solid! Hmmm.

Absolutely no charge to the battery after 8 hours of towing. No change in battery charge level, and battery is new, and accepts a charge from a 110 volt portable charger just fine. Its not the battery.

I HATE electricity, especially trailer-light electricity!!!

[rainjer]

Is you battery grounded?

How may volts are you getting thru the charging pin?

Jeremy

[Gonefishin]

Is you battery grounded?

How may volts are you getting thru the charging pin?

Jeremy

The ground wire from the batery is connected (cleanly) to the ground wire for the rest of the trailer lights, which is grounded (cleanly) to the trailer. So yes, its grounded, but not directly to the trailer. Its grounded via the ground wire on the 7-pin connector.

My battery tester simply has a percentage of charge meter on it, and it goes very far into the "good" range when I test the charging pin. Almost maxed out. I don't have a digital meter.

[dh]

Try disconecting the "hot" terminal from the battery. Check for voltage betewwn the + terminal in your hand and the - terminal still connected to the batteery (with TV running). Just because a cable is new does not mean it is good. Also, try having a helper move the cable about to see if it can be made to "break". Some tow systems use self resetting breakers, so you may have a short somewhere, but not be seeing a blown fuse because the breaker resets itself.