HOTRODS & CLASSICS
WIRE AND FUSE GUIDE
The charts presented on this page are accurate, but some devices may vary in current demands, always follow the manufacturers recommendations for wire size and fuse requirements if they do not match these charts.
WIRE CURRENT RATINGS
| WIRE SIZE | AMPERAGE |
| 8 | 35 |
| 10 | 25 |
| 12 | 20 |
| 14 | 15 |
| 16 | 7 |
| 18 | 5 |
| 20 | 3 |
PLUG IN FUSES
| COLOR | AMPERAGE |
| VIOLET | 3 |
| TAN | 5 |
| BROWN | 7 - 12 |
| RED | 10 |
| LIGHT BLUE | 15 |
| YELLOW | 20 |
| NATURAL | 25 |
| LIGHT GREEN | 30 |
FUSE APPLICATIONS
| APPLICATION | AMPERAGE |
| RADIO | 5 |
| LIGHTER | 20 |
| STOP LIGHTS | 20 |
| TAIL/PARKING | 20 |
| INTERIOR LIGHTS | 20 |
| GAUGES | 5 |
| HEATER | 20 |
| WIPERS | 20 |
| ACCESSORY | 20 |
| OVERDRIVE | 30 |
WIRE GAUGE SIZE APPLICATIONS
| APPLICATION | 6 VOLT | 12 VOLT |
| AMMETER GAUGE | 8 | 10 |
| ALTERNATOR, GENERATOR, REGULATOR MAIN TERMINALS | 8 | 10 |
| ALTERNATOR, GENERATOR, REGULATOR SMALL TERMINALS | 12 | 14 |
| DIRECTIONAL SIGNALS, PARKING LIGHTS, TAIL LIGHTS, RADIO | 14 | 16 |
| ELECTRIC FUEL PUMPS | 12 | 14 |
| GAUGES... FUEL, TEMPERATURE, OIL ETC. | 14 | 16 |
| HEADLIGHTS | 12 | 14 |
| IGNITION, DISTRIBUTOR, COIL | 14 | 16 |
YOU ASKED FOR IT
USING A FORD SOLENOID FOR EARLY GMC STARTERS WITH HEAT PROBLEMS
We know the art work sucks, but we think you'll get the idea. If you can't figure out how to do this conversion from the wiring diagrams below, HAVE IT DONE PROFESSIONALLY. Before proceeding, please read the article in our Question and Answer Section under the Electrical category. Go there now
Below is the typical factory setup
Below is one of two ways to wire the Ford Solenoid to a GMC Starter. In most cases, the Ford solenoid is attached to the firewall. This first way involves leaving the factory main battery lead in place and adding the two twelve gauge wires as shown. This is probably the easiest route to go. The main cable from the battery remain in its stock position and only the key switch start wire is required to be relocated to the Ford solenoid. It goes without saying that you use high quality connectors for all connections.
In this configuration, the main lead to the starter is re-routed to one side of the Ford Solenoid and a cable of equal gauge is then routed from the Ford solenoid to the battery where the original cable connected. A short 12 gauge jumper will be required from the main battery cable post on the GMC solenoid to the original start wire terminal.
