Not sure what you mean. Normally the IGN switch was supplied by a very large direct wire. You can put a large fuse/ breaker inline. I would REDUCE the load on the ignition switch by using the switch to fire a relay (or two) and use the relays then to feed the loads. I've no idea what your overall wiring will "be." For example, if you use a conventional alternator using a regulator with "sensing" (as opposed to a "one wire" alternator) ---part of the problem in these cars (or any other) is that overall voltage drop in the path from battery---through wiring, terminals, and switches---this results in reduced voltage to the VR--and that causes it to overcharge because it "thinks" the battery voltage is low
By using the key to fire a relay you can reduce or eliminate this problem These switches are old and nnot easy to find, and new replacements are low quality
