Modiol, The battery + connects to the starter solinoid bat post. Then a 10ga. wire preferrably with fusible link runs from the solinoid bat. post to the + side of the ammeter. This is the only wire that connects to the positive side of the ammeter. The Alternator bat wire (10 ga.) connects to the - or negative side of the ammeter (again a fusible link is preferred). The ignition switch feed and the fuse block feed also connect to the negative side of the ammeter. You really must have an ammeter capable of handling the power of the alternator. I have gone to a volt meter on my cars for the ease of wiring and the safety aspect. S
PS...the diagram in your last post is wrong. The feeds and alternator connect to the same side (neg) and the hot wire from the starter solinoid (battery wire) connects to the positive side. It is the only wire that is supposed to connect to the positive post of the ammeter.
