Remote battery wiring

[AZFX4]

So I would like to mount my battery remotely behind the seat in my B2. I think I have all the positive wiring figured out. But what do I do with the negatives side. The wire from the post of the battery will go to the frame obviously but what about the two other wires that go from the battery post to the wiring harness? Do i need to run lines all the way back to the battery for these? And what about the block? Can I just ground the block to the frame up fromt and call it good? I have a 4.0 from a 91 explorer.

 

[Spott]

The negative post should ground to the body/frame with a big fat wire. The other negative wires don't matter on a remote battery, clip them off.

Your engine block should already be grounded to the frame and to the negative post on your main battery. If you connect your remote ground to the frame, then it's hooked to the engine and the main battery, through the frame. The frame acts like a big strong wire.

Do you have a charge controller for the dual battery setup? It's best to get a good charge controller, otherwise the batteries will wear on each other a little bit, unless they're perfectly matched (which is unlikely). That will cause the batteries to fail sooner.

Spott

 

[AZFX4]

I'm not talking about dual batteries. Just moving my regular battery to the back.

 

[Spott]

Ah. Makes more sense now.

For the negative, I'd unhook the two little ground wires from the negative clamp, and remove the existing heavy ground wire. Then take the two little wires and work them loose from the wiring harness until you have enough length to run them back to the new battery position. If there's not enough length, solder some new wire onto the ends of the existing wires, and cover the joint with some heat-shrink tubing. Zip-tie the wires (in their new routing) to the wiring harness.

Install the battery behind the seat, and run a heavy cable to a good frame ground. Make sure the spot you're grounding to is CLEAN, with no grease or paint on it. You might be able to re-use the original ground cable for this. Then hook the two little ground wires up to the battery terminal clamp.

Finally, double check that you have a good heavy ground cable between the cab and the frame, between the frame and the engine, and between the engine and the cab. These cables should be as big as the one from the battery to the cab.

That should do it for you!

Spott

 

[AZFX4]

Ok Thanks thats kind of what I figured. But wanted to see if anyone had done this before. You seem to know what your talking about. Im also having an issue with the wiring on the alternator. When I hook up the heavy single wire that goes from the alternator to the relay the battery starts cooking. Something is not hooked up right. I dont know If I have a bad ground somewhere or what would cause this but its not good and no one seems to be able to help me with this.

 

[Spott]

Hmm. That's not what it's supposed to be doing, obviously.

The positive cable from the alternator should hook up to the same stud on the relay, as the cable that runs straight to the positive battery terminal. Effectively, the alternator connects directly to the battery.

I suspect that there's a short to ground somewhere in the alternator circuit. Maybe the cable has rubbed through the insulation, and is contacting the engine. Maybe something inside the alternator connector is bent. Maybe the alternator is shorting to ground internally. Maybe it's something I haven't thought of.

You can best check this with a multi-tester, by measuring the resistance between the positive cable and ground, and then disconnecting portions of the circuit until you find the problem.

Let me know if you need further help,
Spott

 

[4x4junkie]

I have the battery on mine remote-mounted under the rear floorboard.

Those smaller wires that were under the hood I just bolted them down to the frame along with the engine block ground wire (using separate bolts). At the rear I then ran a cable from the frame to the battery negative post.
I also used 2" x 6" pieces of 14 ga. copper sheet on the frame at each connection spot (bolting them down with 3-4 bolts). This disperses the current into the steel frame better, lowering resistance around the connection (be sure to put some dielectric grease between the copper and the frame to stop any corrosion between there).

My positive cable is 2/0 welding cable (0 AWG or even 2 AWG will probably work fine if you're not trying to power a winch).

As for your battery cooking, I would agree, you have something shorted out somewhere (or maybe the alternator has a shorted rectifier block).

 

[AZFX4]

So I went ahead and did my remote battery setup today. Thanks for the help! As for the alternator wire I found the problem. The end of the wire that was connected to the lug on the alternator was bent and actualy making contact with the alternator housing. Bent it back and no issues. Ill post some pics of my remote battery setup soon. Again thanks for the help!