How to Add Hazard Flashers

Having in my classic car collection several British cars, I note that nearly all of them have one feature lacking. In spite of the accepted Lucas practice of intermittent off/on, there is no switch for hazard blinkers. While a lever is provided for (hopefully!) left or right turn trafficators, it would be nice sometimes to have all four corners blinking.

After designing a hazard control circuit box with relay and Hasher that worked fine, and having several cars that needed them, rather than make relay boxes for each, a simpler idea would sure be nice.

There is a simple way to equip almost any car with trafficators to perform a hazard operation. All that is needed is a simple single pole switch, mounted within reach of the driver. Locate the left and right turn feed wires and connect one wire from the switch to the left feed wire, and the other switch lead to the right turn feed wire.

What this does is, with the switch ON, either left or right turn operation of the turn lever will cause both sides to blink because they are connected together. They may blink a bit faster than turn lights, because on some flasher units the rate of on/off depends upon the load (number of bulbs) they feed. The actual connection of the two wires from your hazard switch can usually be made to your existing circuit where the cable comes out of the steering column under the dash.

With the exception of Austin 100s and 3000s, most older British cars use the same color-coded wires in the turn circuit. In MGs, Sprites, Triumphs, and Jaguars, these will be the green/white and green/red wires in the loom. Carefully skin back each of these just enough to be able to connect your switch wire. One wire from each side of the switch to each of these exposed wires, then tape carefully, poke them up out of sight, and prepare for your emergency with confidence. (Note: We recommend you install a 25 amp in-line fuse to each new circuit.—Ed.)

Some Austins use green/yellow and green/blue for color coding the turn signal wires. Refer to the wiring diagram for your car if you are in any doubt.

If locating the wires at the steering columns is impractical, or you just can’t seem to get at them, take a 12-volt test light and with the blinkers flashing left (or right), locate the wire to the flasher, which will be up front near the headlight.

—Jim Rutledge