So you understand the current draw and temps it takes to melt 0ga in half? You got some serious issues somewhere to create that problem and you are lucky to still have a truck and not a pile of charred metal and melted plastic.

There are grounds from the block to the battery, frame to the battery, batter to the fender, drivers side cyl head to pass side cyl head and one under the PCM.

 

Just seen the pics. What type amp and how many watts? I cant imagine the weight load on that truck with the walled box and 6 batteries and having a full size truck with a 3.7L ..... LOL

That cant be helping your mileage...

Is that just 4 twelves or you got more hiding?

 

4 15s and 2 crescendo 3kwp's i clamped roughly 5200rms with those amps on the other alternator, i sent the alt off cus after i fixed the ground i put the alt back in to see if it was the problem and it wasnt charging.

 

i have pass side ground body to block not sure of driver side, have body to batt frame and engine to batt

 

Nice. i wouldnt mind hearing it.

Original wiring of grounds would have been how I listed above. When I did my Big 3 I kept the original routing although replaced wires with 1/0 and added a my pass side battery with add't grounds.

Keep in mind the PCM regulates the alts charging. So if your alt isnt putting out and you are getting other unrelated OBDii codes, you just might have PCM damage. Maybe not.

 

i had an external regulator on the other alt

 

Gotcha. So you think your alt went south then huh?

 

either the alt or regulator

 

Are the batteries held down at all?

If not One bad speed bump and you can short them all out on your metal tool box.
Do you keep some sort of insulation above them?