Ron Francis Wiring is the go-to company for all your automotive electrical solutions. One of their product lines seems to get a lot of questions, so we bring you a brief tutorial on picking out the correct keyed ignition switch for your latest project.

Not surprisingly, the key to choosing the correct switch depends on the size of the mounting hole on the dash. On many vehicles, there is an existing hole and that will determine the choice. The guys at Ron Francis regularly get asked about the physical dimensions of the switches since space behind a dash can differ on any given vehicle. Listed below are three different switches that they sell and their dimensions. Shown are the standard models, however, the company does offer all three with an upgrade to the Synergy Series that use the same switch.

IS-05 IGNITION SWITCH

The IS-05 switch is set up to be dash mounted into a 1-inch hole. This ignition switch has a longer neck than their other two offerings and is wired with a plug at the back. This switch comes with a set of keys, the plug, and the terminals and will wire directly into any of their wiring kits and mounts with a standard mounting nut. The IS-06 ignition switch has the same physical dimensions but comes with a polished billet bezel that replaces the standard mounting nut.

IS-02 IGNITION SWITCH

The IS-02 switch that they sell is very similar to their IS-05 as it is also designed for a 1-inch mounting hole. The biggest difference is that the neck is shorter on this switch, which will suit rear dash conditions with less available space. It will also wire up using a plug at the back. The switch comes with a set of keys, the plug, and the terminals that will wire up to any of their wiring kits and mounts with a standard mounting nut. The IS-08 switch also offers the same physical dimensions but comes with a polished billet bezel that replaces the standard mounting nut.

IS-01 IGNITION SWITCH

The IS-01 switch differs from their other ignition switches because it is set up for a ¾-inch mounting hole. The other difference is how it is wired. Connecting the wires on this switch is accomplished with screw terminals. Included with the switch are a set of keys and ring terminals. If you purchase the IS-07 switch, it will come with a polished billet bezel that replaces the standard mounting nut.

This should answer most of the common ignition questions but for more info, tech assistance, and pricing, go to Ron Francis Wiring.