So I am in the process of relocating the batteries in my dually to the bed for multiple reasons. I started this afternoon with getting the factory wiring out of the way to confirm how it was all ran and make a final decision on how I want to run the new wire. While running new wire, I am also going to a 1/0 awg wire.

The positive wire will be ran just about the same way it is taken off, with a change or 2 due to the batteries being in the bed and not using excess wire. My question now comes to the ground wire. Originally, both batteries ground to the block. Can I ground the batteries to the frame and then the block to the frame? Should I use both ground points on the block and run 2 to the frame? Or should I run the batteries all the way back to the block?

Also, since we are talking about the grounds, what other grounds should I look at upgrading to 1/0 while I am at it?

The other issue I am having is apparently the 1/0 wire I have is oversized and doesn't fit the 1/0 lugs I bought. Is it safe, and effective, to shove the wire into the lug and trim the excess that doesn't fit in the lug? Or should I cut my loses on the lugs I ordered and order 2/0 lugs instead?

Thanks in advance

 

Since the alternator is the charging source, which is grounded to the block via acc bracket, you need the same size and number of conductors connecting the block to the frame as the batteries to the frame.

As for the 1/0 lugs with oversized 1/0 wire, you may have a better connection with the 1/0 lugs and trimming the excess strands than using connectors that are too large unless you have a really good crimper that will do an even crimp all the way around.

 

I like this type of lug...this one is 2/0:
BWD BH404 - Battery Terminal | O'Reilly Auto Parts

 

I would run 0 ga.