[DubK]

Sounds like there's a lot going wrong on this cart. Resistor carts were not meant for 48 volts..so I'd get it back to 36 volts using your best, strongest batteries out of all of them. Hot posts and cables come from loose connections. I've had a battery where I tightened the nut all the way down and the cable was still loose so I had to add some washers underneath. First things first, I'd change out all those old cables to a new bigger 4 gauge or 2 gauge set on the entire cart. Then, if you want to keep this as a resistor coil cart, you can buy a set of new coils. I have a 79 3 wheeler resistor cart that was running bad.. I put a new higher amp solenoid, new 2 gauge cables, new coils, and a heavy duty forward reverse switch on the cart and it ran great after that and felt a couple mph faster but that could have been just in my head, but sure ran great. I then broke a terminal off of the motor like yours is from not using 2 wrenches while working on it, tried to repair it but it kept arcing. I'm not sure an aftermarket motor would fit that perpendicular rear end. But I ended up putting a newer style parallel motor rear end on it from a parts Marathon with a controller set up that I got for $200. Motor was sent off to Plum Quick for a rebuild, and I'm currently in the process of swapping over some parts to make it a solid state cart with a new 500 amp controller and when it's time for batteries I will go with 48 volts. Highly suggest doing a solid state conversion on your marathon. It was make it so much more efficient and opens up a world of upgrades. You can do it the cheaper route like me by using a parts cart (90-94 marathons were solid state controller carts), or Scottyb from cartsunlimited.net sells a solid state conversion for these carts. Game changer!