The Stovebolt Site Forums The Shop Area The Electrical Bay Original ignition to 12v question

We're working on the wiring of my 1946 Chevy 1/2 ton. Completely new wiring harness - nothing original.

There's three "ignition" wires from my harness and only two terminal lugs on my (1946) ignition - which ignition wires do we connect, and what should I do with the unused one?

Wiring harness is JEGS 10411.

Ignition coil - pink
Ignition accessory - orange
Ignition power- red

Give me the names and numbers and colors of the four wires. I have the instructions on my screen. It would be really great to have a pic of the back of ignition switch or vendor part number. What are the names marked on your Ignition switch for ALL the terminals? I know you have more than "two spots"

I Assume you have Alternator? Ballast resistor?......... HEI or points distributor?....or pertronix?

MONITOR your post today

Did you get the instruction sheet from JEGS with it? If not, HERE is a link to the instructions.They have a number of diagrams depending on what kind of ignition system you have. Most have multiple wires to a single terminal. If you have the original distributor, then follow the original wiring diagram and ignore the extra wires.

@bartamos, thank you! There's only three ignition wires, not four. It's an original '46 ignition, and there's only two terminals.

Ignition coil - pink
Ignition accessory - orange
Ignition power - red

@klhansen - We have the diagram, thank you for the link! It's a modern harness and a 'primitive' (1946) ignition...we're trying to make sure we connect the correct ones so we don't have to backtrack later.

You can't use that switch, get a more modern look alike with three or four terminals. Give me the wire numbers you want to connect.

Do you have an ammeter gauge in dash ? These kits do not support an ammeter, Do you have a volt gauge in dash?

@Bartamos - Thank you! That's what hubby was afraid of. I'm trying to keep it as original as possible, and he bought one me one identical to the one that came with it. I appreciate your time and help.

OK no problem. I've edited my above post. please answer the questions. It's OK for "non original" to get a newer switch just like you went to 12V. Some things are necessary when converting to 12V and want more modern safety and reliablity.
Like, Ign sw, ballast resistor, alternator, 12V bulbs, voltage reducers, 12V coil, new harness, etc....... Better be sure your distributor is convertable, Notsure about that. Hotrod Jerry can advise. Don't know about where that "cable" from ignition switch went.

@bartamos - I have my original instrument cluster. Ammeter - not using it. We'll probably add a voltmeter in the dash, but we're not 100% sure yet. No LS Swap, big motor, bells, or whistles. It was an old farm truck from Kansas that I'm leaving as original as possible. I thought about connecting the "stomp pedal" but, since I probably wouldn't use it, we probably won't hook it up.

Using ignition wire numbers 33, 31, & 34.

@bartamos - Distributor, ignition coil, starter, and alternator are all 12V. My 216 Babbit was completely seized, and I replaced it with a 261 (235 with captain bars) from a 1961 Square body.

I'm grateful for the thorough help! Hubby has a 1968 Camaro that he's had since high school so this is our oldest (his second/my first) restoration. All advice is greatly appreciated! =)

OK good, so now you have an electric starter solenoid type starter? NOT the one shown in your pic?

I'm going to tell you about 31, 33, 34 when I get all the info I need.
Go to email, too much to say on here. Click on my user name at top of post. "bartamos" then profile .....you will see my email to click.

You really thru me for a loop when you said you may not use the foot start!!!!!!!!!!!!

If you look at these two together, you can see what is expected.

Wire 34 (Batt) is the power coming in from the battery
Wire 33 (Acc) is power out to things on the accessory line. Generally speaking, that is things that are powered in the run or acc position of the key.
Wire 31 (Ign) is power out to things on the ignition line. Generally speaking, that is things that are powered in the start and run positions of the key.

If you are not adding extra stuff to the truck, your existing switch should be fine, but some measurements are needed.

Do you have a multimeter to see what terminals are connected in what key positions?

If you are adding a solenoid starter, you will need a new switch with a start position. In that case, hook up the wiring as shown in the documentation.

@Fibonachu - Thank you for the information! (Yes, we have a multimeter.)

To check your current switch, mark the three terminals (how doesn't really matter) so you can ID them going forward.

Then use your multimeter to see which terminals are connected in what key positions.

Example:
Key out: no terminals connected

Key in, position one:
-terminal 1 connected to terminal 2
-terminal 3 unconnected

Key in, position two:
-all three terminals connected

If you can give us that info, we can help you further.

Maria - Not to try and throw any wrenches into the conversation, but from what I have read so far one of the key items you seem to be planning to use is an original style "electrolux" ignition switch like the old worn out one you have pictured above (has the metal shielded cable that goes to the distributor and two wire connection posts). You mentioned having another serviceable switch to replace that one. Is that correct or are you changing to a different style ignition switch?

Some of the information mentioned above doesn't directly apply if you are planning on using that original switch, so to try and get your plan and possible answers better clarified, can you answer that question please? Once folks know what switch you intend to use, that can help folks put together more accurate suggestions and guidance on what wiring connections are needed and where. It won't be the final answer, just getting things sorted out to work with what you have and intend to use. Details on everything included in the plan will help piece it all together even more.

Thank you for the replies!

Pictured here is the ignition switch that my husband ordered yesterday (once we realized that the NOS 1946 i/s wouldn't work with the modern wiring harness).

Thanks for replying Maria and being willing to listen to all of us fellow truck nuts - lol! For others re-looking at your wiring question related to now using this switch, it's described as:

The Pollak 31-180P is a 4-position ignition switch with a die-cast housing, offering functions for Accessory, Off, On/Accessory, and Start, with a momentary start feature and a universal fit.

That switch should come with a wiring guide and IMO will work with your planned solenoid actuated starter, the 12volt new harness and the other electrical items you mentioned. Perhaps one of electrical guru's can better describe which wire goes were, etc. now?

Best of luck with the continued work on your truck!

With that switch, wire 34 goes to "BAT", wire 31 goes to "IGN", and wire 33 goes to "ACC".

If you keep the stomp start, you would turn the key to the run position, then start it with the stomp switch.

If you change to a solenoid (key) starter, then connect wire 19 to the "ST" terminal.

I am working off line with husband and wife team to sort out what they have and what they want. Will return after that.
I apologize for saying "I know you have more than "two spots", they did only have two spots on that old ignition switch.

@ Gdads51 - I appreciate any and all help and advise! Hubby and I both deal with wiring and cables for the Navy (he's more wiring and I'm more cables) but getting a 79 year on truck on the road in 2025 is outside of both of our wheel houses. LoL

@Fibonachu - Thank you for the information and diagram! I'm still trying to wrap my head around the stomp start because it's been 25 years since I drove a late 1980-something manual. 😅 I think it'll be a neat feature, especially since only one out of about every nine or ten 41-46's I see is original.

@ Bartamos - No worries! One of our son's friends/our friends is helping us... I was just typing what the two of them were saying as they discovered things. I'm trying to re-familiarize myself with my truck since we started dismantling it five years ago, and I was 110% novice when we began.

New question. =)

I'm running my original instrument cluster, swapping 6v to 12v (1946 Chevy truck). What type of light bulb sockets will I need, and how many? I assume just the bright light indicator, turn signals (I've got a 1950-something turn signal for safety) - that's three... How many more, and what sizes, please? Or where can I find out? Thank you!

If you are using your original speedometer and instrument cluster, you will need the same snap-in sockets that were originally used in your truck. If you have changed to a different wiring harness, the bulb sockets with it should be the same. If they are not, then you'll need to cut/splice/solder and insulate to change them. All of the 6v bulbs have 12v equivalents. The clear 12v bulbs will be sold as bulb #1895 and are available lots of places. Hope this helps. I don't know what turn signal type you have but you can take each of those to your local auto parts store and find the 12v equivalent.

Thank you so much, Jon!