[wizard]

Do you know how to use a volt meter?
Even though the wire may be located in the right place, it does not mean that the voltage is there. A VOM (Volt/Ohm Meter) is indispensible in diagnosing eletrical problems. Your High beam problem could be a wrong wire, loose wire, bad switch, blown fuse etc. Again, a VOM would be most helpful. The Ammeter might be wired backwards. Seems to be, but I would verify the wiring as well. If it is wired backwards, which end? at the meter or where you pick up the Voltage. Let's say you reverse the wires at the meter and all works well and actually you had reverse-wired the other wire ends, you'll have a case of 2 wrongs making a right, until you have to trouble shoot it later or worse, the guy you sell it to and didn't tell because you didn't know.
If you're going to work on these kinds of cars, not trying to sound harsh here, you either need to learn some electrical basics or know someone who does.
I'll certainly help if I can.