Battery required in circuit for tow vehicle????

hoefler

Well-known member
Charge line from truck goes to the battery. The charge line from the convertor goes to the battery. The power wire from the fuse panel goes to the battery. Sensing a pattern yet? When all these wires are connected at the battery, you have a completed circuit. When disconnected, no circuit.
 

jsanders

Member
Thanks hoefler. Yes, I learned that the hard way before learning here and from my wiring diagram in manual. The Heartland is new to us as we replaced our smaller travel trailer.
 

Jim.Allison

Well-known member
What you say is true except he has no dangling wires.

Each one, the battery, the converter/charger, and the TV and a solar charger are energy sources and should not be dependant on the battery or any of the other components. Each one should be parallel and if hooked into the battery leads should provide energy to the system with or without each of the other components/energy sources, including the battery. IMHO. As far as the fuse panel receiving power from the battery, that much is true, but the fuse panel is actually connected to the battery leads as is the charger/converter, and the TV, AND solar if you got it.

The battery is just an additional power source and a energy storage device in the system.

If he is not getting power from the TV to the fuse panel without the battery, there is either a protection device installed somewhere or it is wired that way on purpose, or he has a broken connection.

It is probably a broken ground. DC does not like chassis ground, a chassis ground corrodes and creates resistance. I would find that chassis ground and run an additional ground via a copper wire (green insulated wire available at lowes) from that same chassis ground the grounding buss bar, located in the battery box. In fact any chassis ground that you find on your rig should be augmented by a direct copper wire back to that buss bar.

If his rig requires a battery to be installed before his TV can provide power to the rig then he is, without a doubt wired differently than I am. It could be wired that way on purpose.


Charge line from truck goes to the battery. The charge line from the convertor goes to the battery. The power wire from the fuse panel goes to the battery. Sensing a pattern yet? When all these wires are connected at the battery, you have a completed circuit. When disconnected, no circuit.
 

hoefler

Well-known member
I researched and spent much time trying to find what was wrong with my new Silverado round connector to not give power inside travel trailer. I had the battery removed from camper for charging. When I put the battery back in battery box and connected it, the lights in camper functioned from the 12 volts supplied from the truck. Must battery be installed in the circuit for tow vehicle to give 12 volts to interior of camper?


He had the battery removed. The battery is a wire junction point.
 

danemayer

Well-known member
I think the 12V wiring from the tow vehicle is either spliced to the trailer positive battery cable at the post connector, or connects through a circuit breaker at the buss bar. In that situation, the power from the tow vehicle would be available to the trailer whether the positive cable was sitting on the battery or not.

But a ground path is necessary as well. If not plugged in to shore power, perhaps the ground path is dependent on either the trailer battery or the tow vehicle battery. When the trailer battery is in the circuit, apparently it is providing a ground path. When the trailer battery is not in the circuit, it appears to be lacking a ground path.

That makes me suspect an open circuit in the ground wiring between trailer and tow vehicle battery. Might just have a weak ground contact on the 7 pin connector.
 

whp4262

Well-known member
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I've never tried to run any 12v stuff in my camper off the truck without the battery connected. I'll have to try it and see what happens. If you find that the coach battery is not charging off the truck it will probably be one of the breakers in the attached picture. On mine it's the breaker on the far right. Also the battery disconnect would need to be in the on position if your coach has one to get power from the truck to the inside of your camper.


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whp4262

Well-known member
Update. Disconnected the coach battery, plugged the trailer into the truck, turned the battery disconnect switch on and I have 12v power in the camper from the truck without the coach battery in the circuit.


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danemayer

Well-known member
depending on how the wires come together this may not be conclusive. try with positive cable disconnected from the battery post.
 

whp4262

Well-known member
depending on how the wires come together this may not be conclusive. try with positive cable disconnected from the battery post.[/

When I tried it I had the cables disconnected from the trailer battery. If you look at the picture I posted you can see the heavy red battery cable from the trailer battery. There is also a smaller red wire routed with this cable, that's the power wire from the tow vehicle. The smaller red wire is connected to one side of a circuit breaker and the other side of the breaker is connected to the big red battery isolation switch on the same terminal as the trailer battery positive lead. So if this switch is not on power from the TV can't get to the trailer. But the TV will charge the trailer battery regardless of the position of the isolation switch.

Danemayer are you going to be at Santo?


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