Trailer wiring

wesel123

Explorer
Sometimes Mud gets a little nasty so Ill ask here.

How on gods green earth do I run the battery charge cable on my 100 for the trailer battery???? Does it run from the alternator (I have a 200w Mean Green) or does it run from my second battery and if so pos or neg???? Help!!!!!1
 

adventureduo

Dave Druck [KI6LBB]
That's a very good question........ that i wish i could answer. Our 80 charges our dual AGM's in the nose box of our AT while driving. The only thing Mario told me to do when i had the brake controller installed was run heavier gauge wiring than normal for the positive lead. I think he said 8 or 10 awg. Other than that... i don't really know where they are bringing the power in from. That's a really good question that i never even thought about!! Now i want to know too.
 

elcoyote

Supporting Sponsor, Overland Certified OC0004
Run it from the 2nd battery (I am assuming that it is isolated from the starting battery). Connect a 10 ga wire to your positive terminal with a 25 amp fuse or circuit breaker.
 

wesel123

Explorer
Run it from the 2nd battery (I am assuming that it is isolated from the starting battery). Connect a 10 ga wire to your positive terminal with a 25 amp fuse or circuit breaker.

Sweet I did that...

So on the trailer end the wire runs to the pos or the neg on the trailer battery??

(Thanks once again Mario:))
 

ntsqd

Heretic Car Camper
They want to be in parallel, so positive to positive, negative to negative.
 

njtaco

Explorer
I di that too but kpe blowing the fuse???? What the heck??

Were you tying to charge a near-dead or dead battery with the 200A alternator? Of course the fuse will blow...try a circuit breaker instead, it may be more tolerant of the initial surge. Otherwise, trickle charge the battery back to life, and don't let it go dead again. Do not put a larger fuse or breaker in than the wire is rated for at the length of the run.

In the field, where no trickle charger is available, take the dead battery out of the trailer, and use 4 ga or bigger jumper cables to coax it back to life. This isn't great for the battery, as you are charging it "too fast", but then neither would letting it go flat dead in the first place. Assuming that is what you are doing to begin with...

Otherwise you have a dead short to ground on the fused wire, or are wired wrong.
 
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wesel123

Explorer
No I have a fully charged yellow top set up as my second battery (done up proper with isolators and such) and the 10 gage wire running from the Pos to the rear of the truck. I have 1 12volt socket of this wire (spliced in) and that's it.

I then have a 10ga, wire coming for the pos on the RV battery and when I connect the 2 I pop the 20amp inline fuse up at the point of connection...hope that's not confusing??
 

elcoyote

Supporting Sponsor, Overland Certified OC0004
No I have a fully charged yellow top set up as my second battery (done up proper with isolators and such) and the 10 gage wire running from the Pos to the rear of the truck. I have 1 12volt socket of this wire (spliced in) and that's it.

I then have a 10ga, wire coming for the pos on the RV battery and when I connect the 2 I pop the 20amp inline fuse up at the point of connection...hope that's not confusing??

You have a short. You need to fully evaluate the wiring on the trailer and on the vehicle to find the source. What trailer plug configuration are you using the make the connection? We often see incorrectly wired plugs & sockets as the root cause.
 

rambrush

Adventurer
A 10ga wire is only good for 30 amps, did you you take your meter and test the wire to ensure its not grounded? Test each side of the circuit inbound and out bound to determine which way to go.
Trailers with out ac use a 30 amp circuit if it has a ac its usually a 50 amp.
 

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