Turn Signal Switch Operation

[charleypete1957]

In my FSM I’ve stared at that turn signal switch diagram for hours trying to figure out how it’s meant to operate. I’ve dabbled in electronics since I was fifteen and was an electrician before I retired, and I’ve never seen a switch drawn like that and can’t figure out how it works. Seems like every terminal is connected to every other terminal all the time, and what are all the dotted lines for? You’d think they could have drawn the thing in some sort of conventional manner. Any enlightenment out there? Oh and thanks to whoever is behind keeping this forum up and running. Thanks for all your hard work, time and energy for keeping things here going. We’re all in your debt.

[PwrWgnDrvr]

The white wire feeds power to both left and right circuits for the brake lights when the switch is in the center position. That is the position with solid black lines. When in turn position, one half of the dotted lines indicate the signal circuit, depending on whether left or right, and one half of the solid black lines indicate the brake light circuit for the side not signaling. Power for the signal side is fed from the red wire on the center terminal at the dotted lines.

The whole thing is definitely poorly done. The short vertical lines between terminals are misleading and erroneous. If you understand the necessary circuitry it can be figured out. One must remember that the sig switch has to disconnect the rear filament from the brake light circuit when signaling because brakes and signals use the same filament, all while also energizing the front signals.

Hellbelly (Scott), Hobcobble (John) and CSS Registry (Ben) are the hardworking techs that spent all these days doing major upgrades here.

[charleypete1957]

Thanks so much for that explanation. I would never have figured it out on my own, I’m sure. I’m in the process of trying to adapt a 1983 Ram tilt steering column into my 1970 D100. The mechanical part I can figure out what changes need doing, but the turn signal switches are not the same, as the ‘83 switch incorporates the hazard lights. I’d like to keep the original D100 hazard lights as they are and bypass that function on the newer switch. With your explanation, I think I’ve got it figured out. I wanted to just incorporate the original switch into the newer column, but it won’t physically fit, which is why I decided to go with the newer switch. Anyway, it should be doable. Thanks again!