86 Marathon FnR issues

[EZglider]

Hi,had this resistor cart given to me by my father-in-law,hasn't been run in several years. I've replaced the batteries, all the battery cables,the main solenoid mounting board with contacts,and the position switch. It also has the improved heavy coil resistor. It moves in forward and reverse ok,but sounds like its arcing when you're driving,accompanied by burning smell. the new contacts seem scorched already. Would a bad F &R switch cause that? Will also move forward/ back without key switch even being on. I freely admit to ignorance on these rigs,just want to use the old nag as my yard mule...won't ever be putting it on display or racing it,practical usage is my goal. Thanks,everyone,hope to hear back.

[coosa]

Moving with the key switch on could be a bad microswitch or a welded solenoid. I didn't understand from your post if you replaced the solenoid itself? If you didn't, sounds like it could be your problem.

Also, check out the wiring diagram above and make sure you have all the cables on the speed control. There is one that it will run without, but it greatly increases arcing. Good luck with it

[EZglider]

I'll try replacing solenoid and recheck wiring for correct routing,thanks

[Andy4639]

On these old resistor carts what you are saying sounds normal to me. The contacts would have to be perfect not to ark. The burning smell is the coils burning off the energy. Pretty normal stuff.

Check the spring loaded swipper contact and make sure it's moving freely when it swippes across the other ones.

[Brob1969]

The F/R could be arcing. I would pull it apart and check the contacts.

[Andy4639]

If the cart doesn't run when turned off and nothing is heating up then the components are fine. Yes the forward Reverse could be melted and needs replacement.