Signal Switch 3Wire 6v Hookup

[Bobby Rodd]

 I have a vintage KD signal switch (with 3 wires coming from it) and am trying to figure out how to wire it into my ‘37 Buick.  How can this be done? I’m only a hobbyist and need your help!!

BobbyRodd

[Morgan Wright]

You need to hook up test lights to the different wires to see what they do, maybe just a multi tester. One wire is left, one is right, and one is power, but you can't tell  by just guessing.

[McCargar]

Usually the green wire is RIGHT and the yellow is Left and the black/red to the "L" terminal on the flasher. A three wire switch only works with a single use bulbs not with a stop/signal combination. 

[Morgan Wright]

'39 and '40 which were the first years for turn signals had separate appliances for them. The stop lights and tail lights were together on the tail fins, the turn signals were on the trunk. If you want to make your car look snazzy, get a '39 or '40 BUICK EIGHT turn signal fixture.

[Bloo]

A 3 wire unit wont wire into anything really, you need separate light housings. The wiring will all be new and separate.

 

       6v >> flasher input pin

       Flasher output pin >> center contact of switch

 

and then...

 

       Right switch contact >> both right hand bulbs

       Left switch contact >> both left bulbs

       If you are going to have have two turn signal indicators (inside the car), hook one to each side.

       If you will have only one, hook it to the third pin on the flasher.

 

and finally....

 

       Make sure all sockets are grounded.

 

On a 1937 Buick is it probably possible to change the parking light sockets for dual contact sockets, and dual filament bulbs, and put the front signals in with the parking lights. On the back you would still need to add separate lights.

 

 

[DonMicheletti]

You definitely can adapt 2 filament bulb holders in the parking lights on the '37.  I did it on my '38's.

 

To easily include the stop lights and turn, you should try to get a 7 wire switch, such as the "Auto Lamp" 9000

 

 

[McCargar]

If anyone is interested there is a way to use single filament bulbs as dual function bulbs. All you need is 4 little double pole double throw relays. wiring diagram attached.

[Daves1940Buick56S]

And you could take it one step further by hooking the parking light switch output to the 2 front signal light normally closed terminals.

 

Cheers, Dave

[McCargar]

Dave you are right I posted the wrong drawing.