Mine is an 89 ram van chassis. I put a doubled 4awg jumper cable from alt(+) stud 11 feet to my Blueseas 6007m manual battery switch's common stud. I butt spliced and Extended the alternator's original 6awg ground cable with 4gauge to My drivers side Head. To this same head bolt goes a 4awg cable to my 500 amp shunt, and another 4awg cable to my frame. From this same frame bolt goes another 4awg cable to the alternator (-) stud.
All frame and engine grounds were filed and polished to steel mirror status. All use thick walled tinned copper lugs and smeared afterwards with thick grease.
My original 10 inch Fusible link on the 6awg cable from alternator to engine battery was 10 awg. A automotive electrician found and replaced it for me long ago with a 4 inch length of 14awg fusible link. It would get so hot I could not hold it in my fingers when the batteries were depleted. My doubled jumper cable(+) is in parallel to this original circuit. I have a 140 amp circuit breaker on the jumper cable. Disconnecting this breaker and my alternator output diminishes by over half when the batteries are depleted.
