very common on the old doge trucks and cars, the volt reg is on the firewall, take it off and clean the firewall and back of the reg up with sandpaper and remove any paint or rust, the regs are self grounding. Check the field wires from the reg to the alt and make sure they are good and no bad connections. They are 2 small wires like 16awg. If there is still a problem just get a new reg at the parts store, they are like $20. There is nothing to bypass as the reg is already external. Dont put a 1 wire on. You dont need to get an expensive adjustable that you need on gm, ford, and imports either. The old setups are actually pretty cool as you can plop an adjustable right in place of a stock one, no rewiring or anything. Here is an adjustable about half way down the page.
STARTERS AND ALTERNATORS