trhamilton,
This is my second try at this post. It sounds like you have a few things wired wrong...I think. No wire should run from the ammeter to the solenoid. The 'S' terminal pulls the starter in when the key is turned to START. The keyswitch should receive power from the - side of the ammeter, along with all the other loads in the system. The 'R' terminal is a bypass terminal which is only powered (internally) when the solenoid is pulled in. This bypasses any ignition resistor for a full voltage START.
You need to 'ring out' your ignition switch and find the terminals that are common when the key is turned to START..these will be your feed from BATT to solenoid. Does this make sense.
I will clarify a previous statement. A wire will run from ammeter to solenoid, but it runs from the + side, it's a large wire, and it is the path for the charging system to BATT.
Stuart