Basically, power flows from the battery through this fuse or fusible link to the ignition switch. It powers the accessories, ignition 1, and start 1. Start 1 goes to the engine control module (ECM) and starter solenoid. Ignition 1 goes to wipers, ECU, turn signals, rear heater, and the diffs. Accessories - cig lighter. Most of these circuits are fused separately. AM1 is like the main.