66 EM flasher option

[Mach1 Driver]

I don't have a 66, but I'm looking into the emergency flasher option. It has a couple of plugs that connect into the OEM harness and the switch gets located in the glove box. It has what appears to be a DPST switch that 4 wires connect to. Having investigated the circuit, the only way I see for it to work as shown on the wire diagrams is if the switch is actually 3PST. Is anyone aware if that's the case?
Hopefully Randy will wander in here and know... wasn't his car "Midlife" a 66?
If its only a DPDT, the switch would need to be turned on and the turn signals turned on for the fronts to flash- with the ignition off. This wasn't well thought out. Later years have it as a standard feature and use a 4PDT switch to separate the circuits and get rid of all the possible nasty side effects.

 

[Midlife]

It is a 3PST switch.

 

[Mach1 Driver]

Thanks Randy, a 3P switch will clean up the operation considerably, but even then, if the ignition, turn signal and hazard are on at the same time, the lights won't blink. On the 69 the hazard is a 4P switch to disconnect the normal flasher and eliminate the "no blink" situation.