Wiring

[Taylormade]

I posted this in the Technical section, but I'm hoping some DB fans might have the answer.

 

There was little left of the wiring in my 1932 dodge Brothers DL sedan when I got her.  Now I'm ready to rewire the car and have a question for all you wiring gurus out there - electrical systems are not my forte.

 

The car originally came with one of those infamous coil/ignition units that had the ignition key built into the coil.  These are still available, but at $250 I'd rather save a few bucks and use a regular coil, since it's hidden under the dash anyway.  In fact, the car ran on this setup when I first owned it and never gave me any problems.  This is the replacement ignition switch that has always been in the car since I owned it.  It has three terminals, IGN, BAT and STA.  Although I took pretty good notes at the time of disassembly five years ago, I can't locate the one sheet I need - how the switch was wired up.  I have a new Rhode Island Wiring harness, but it is designed for the coil/ignition setup.  So, how do I bypass that and wire it correctly for the current ignition switch?

 

 

The green wire went from the STA post on the key switch to the negative post of the coil.  The wires on other two terminals - your guess is as good as mine.  The switch is a simple on and off - just two positions.

 

Here is the wiring diagram for the original wiring setup.

 

 

 

It's a positive ground car. 

What gauge wire is usually run from the positive terminal of the coil to the distributor on a six volt system?

 

Any help or suggestions greatly appreciated.

 

[David_Leech]

I am having a hard time following this diagram. Here is how it is on my 28 standard six

 

The battery terminal of that switch will go to battery neg. The ignition terminal will go to the neg terminal of the coil. The pos terminal of the coil will go to the breaker points. The breaker points will go to the condenser and then go to pos ground. STA would go to the starter and should only be active when the switch is in the momentary starting position. It will be inactive after the key self returns to the ignition position. (On a three position switch, yours is only on/off? Both diagrams show the switch as two terminal) If you have a floor mounted starter switch, just leave this terminal unused. In the original coil/switch setup, the ignition wire to the coil was all internal to the component. You can use 14g wiring, it will be fine. Remember, the Lower the wire number, the HEAVIER the wire is

Edited July 28, 2018 by David_Leech (see edit history)

[David_Leech]

In the older diagram, let's replace the ignition switch/coil with a two terminal switch and a seperate coil. From the top down on the drawing of that switch, this is how we will wire it up

 

The top wire is running to the  breaker points. Let's connect it to the "pos" terminal of the coil. 

 

The middle wire is running to the  gas guage. Let's connect it to the "on" terminal of the switch

 

Now we need to supply the new coil  with a negative, so we will run a new wire from the "on" terminal to the "neg" of the ignition coil

 

The final wire is coming from the ammeter. This can be traced back down to the battery "neg" if we follow it back far enough. Connect the this wire to the "bat" terminal of the switch.

 

Now, when we turn the switch "on", the coil and gas gauge are all supplied with "neg" from the battery

[Taylormade]

My car has a mechanical foot pedal to start the car.  My switch has only on and off positions, at least it seems that way - when I turn the key, there is no detention or middle stop, it just turn all the way to a solid stop..  With it off, I get no continuity between any of the three terminals.  With it on, I get continuity between any two terminals, doesn’t matter which two.  With just the main wiring harness hooked up and nothing wired under the dash, the starter works fine.

[David_Leech]

The ignition and start must be the same electrically. Just wire it up with one going to the gas gauge and the other going to the coil. It won't hurt anything. See if it runs. You could even bridge the two to be sure

Edited July 28, 2018 by David_Leech (see edit history)

[Taylormade]

Thanks, David, I appreciate the help.  I’ll let you know how it works out.

[ply33]

4 hours ago, Taylormade said:

My car has a mechanical foot pedal to start the car.  My switch has only on and off positions, at least it seems that way - when I turn the key, there is no detention or middle stop, it just turn all the way to a solid stop..  With it off, I get no continuity between any of the three terminals.  With it on, I get continuity between any two terminals, doesn’t matter which two.  With just the main wiring harness hooked up and nothing wired under the dash, the starter works fine.

 

Sounds the same as my '33 Plymouth other than the fact that one of the three "terminals" is actually an armored cable going to the firewall mounted coil.

 

In my car, you have power supplied to one of the terminals by a wire from the ammeter. The other non-armored terminal feeds the gas gauge. Simple on/off operation where all the terminals are isolated when off and connected together when on.