put a ground strap from the battery to the frame and a strap from the frame to the engine/bellhousing. have good contact where the straps connect and you wont have any issues. good grounds and good clean connections are the key to keeping a six volt system working as designed. also make sure your using a 2 ought cable or larger as battery cables to let the current flow unrestricted. my 6100 sits outside and i started it the other day from not running it since november. after i got the fuel up if fired right up and it spun like it was a summer day. all my trucks are six volt and i have no issues with them and the batteries are at least three years old.