1967 Valiant Signet Electrical Proble Please Help I need a Pro

There are a gazillion posts on the electrical problems you are having. You can do anything from a quickie fix to a full re-wire (as I and 67Dart273 did). Best way to bypass the ammeter is to run an 8 awg wire from the big stud on the alternator direct to BATT+. If you bypass it in the passenger cabin, you still rely on the bulkhead connector, which is the main problem area for 1966+ cars.

Your erratic dying problem is almost certainly in the bulkhead connector or (less likely) a bad ignition switch or erratic ballast resistor. The Mopar electronic ignitions are not known for reliability. HEI is a much better design and gets rid of the ballast resistor.

It sounds like once it wouldn't turn over until your friend connected jumpers, even though the battery was charged. That is very common corrosion at the battery terminals. I had to remove and clean the terminals every few years when I lived in GA, on all my cars. Ask at any auto parts store for fixes.