I have a 1975 dodge motorhome class c, when key is in accessory position fusible link from battery to firewall gets warm, when vehicle is running it gets very very hot, if i disconnect ballast resistor when key is in accessory position it doesn't get warm, jacket on wires connected to coil are very hard for about 6 inches. I'm also not sure what to search when i go onlie or parts store, it's it a van or truck, mb30 doesn't come up at any parts store search, also it's the a specific plug wire routing diagram, i have 63 mercury fe and i believe wires 6&7need to be wrapped around once. Thanks appreciate any and all help

 

Might have a problem with dirty or corroded connections... Check the one going threw the firewall first and make sure it is in good condition. Make sure all the grounds are clean and tight.

If you get one of the kits like this, it comes with the wire you are looking for. If you just need the wire, e-mail and see if you can just get that?
https://www.jegs.com/p/Proform/Profo...52042/10002/-1

For the 1963 Ford FE... I would get a set of Accel Super Stock wires or something of like kind and make what you need to the correct length.
https://www.jegs.com/p/Accel/Accel-S...47765/10002/-1