[DaveInCanada]

Hi All,

I have re-run the wiring harness in my 57 Super Chief and I'm having issues with trying to get the motor to start. I'm worried that have wired things wrong. I have a few questions:

1. Does a 57 Pontiac have a starter relay (doesn't look like there's one)?

2. What wires should be connected to the positive terminal of the starter solenoid (other than the batter cable)? Colors or drawing would help

3. Should there be a wire running from the ignition coil to distributor? (not referring to the spark wire). Note: I upgraded to Pertronix ignition module in the distributor.

Some of these questions may sound silly, but I'm a novice when it comes to wiring and I'm having to re-wire with the original harness from scratch. And the shop manual diagram is difficult to follow. Thanks for your help.

Dave

[johnta1]

The battery cable connects to the big post on the starter. (at least later models, don't have a 57 manual with me)
Some have a horn relay but don't think battery cable goes to it first?

Anyway, there should be a wire that goes from the switch when in cranking position to a smaller post on starter. If more than 1 small posts, need more info.

When power applied to the small post from ignition switch (just thought it might have a floor mounted switch to crank, maybe?)

That small wire activates the starter relay which makes it crank.

The distributor should have the negative post wire from coil connected to it.
The + side of coil should have 2 wires probably from ignition switch so when on or in cranking position applies power to coil.


If engine cranks but does not fire/start let us know.

[DaveInCanada]

@johntal Thank you very much. Any chance you might have drawing or schematic?

[Bill Hanlon]

Thanks to Larry Gorden the original 1957 Pontiac wiring diagram can be found here:
https://www.pontiacsafari.com/57/Sho...nstruments.pdf

I know very little about the Pertronics unit, but if it all fits inside the distributor you'll need to bypass the stock "coil resistor" (that's what it is called in the Pontiac wiring diagram, sometimes known as a ballast resistor) so the coil primary terminal (+) has a full 12 volts when in crank and run.

[DaveInCanada]

@BillHanlon. Thank you for the link. Yes, the Pertronix unit fits inside the distributor. Thank you for letting me know to bypass the resistor. I still have it connected.

[DaveInCanada]

So according to the diagram on page 12-28 it looks like there is wire going from the coil to the distributor. Right now I don't have a wire running from the coil to distributor.

[johnta1]

You need that wire!
The distributor should have a wire hanging down from it?

Does the engine crank over?

[DaveInCanada]

No, the engine does not crank over.

The other question is about the wires to starter motor. I have a large yellow wire and a thinner purple wire connected to the starter. Are they supposed to be on the same terminal? Is one supposed to be on the battery terminal.

[Bill Hanlon]

Originally Posted by DaveInCanada

The other question is about the wires to starter motor. I have a large yellow wire and a thinner purple wire connected to the starter. Are they supposed to be on the same terminal? Is one supposed to be on the battery terminal.

In the column of text at the right side of the wiring diagram I posted you will find an entry for "Starter". It says there should be a yellow wire from the battery and a purple wire attached to the starter solenoid.

The big yellow wire connects to the large stud on the solenoid.

The purple wire attaches to the small stud on the solenoid. If there are two small studs (like shown in my attached picture) connect the purple wire to the stud marked "S".

[DaveInCanada]

Great. I will have to recheck how many terminals are on my starter.

I can't see a wire hanging from my distributor. I'm assuming it may have been removed by the previous owner when he swapped in the Pertronix module while the engine was out of the car. I'm guessing I have to attach a new wire to the distributor somewhere in the housing.

[johnta1]

The pertronix should have a wire that comes out of the distributor?
If not, something may be wrong with it?


Taking cap off should show something I guess.

[DaveInCanada]

Hey Guys,

The yellow and purple wires from the starter go into some sort of connector that an extra red wire running out the other side. Any idea what this is? A junction of some sort? See attachment.

[Bill Hanlon]

That yellow wire isn't near big enough to be the wire attached to the big lug on the solenoid. The yellow wire mentioned in the wiring diagram I attached above would go directly from the battery's positive post to the big lug on the starter's solenoid.

When you say you "have re-run the wiring harness in my 57 Super Chief" do you mean you are just reconnecting existing wiring or are you replacing existing wiring? Are you working with what you think is original wiring or is it a generic after-market harness?

[DaveInCanada]

I have three terminals on my starter. One large, one medium, one small. I know the small one "s" is for the purple wire. I assume the largest one is for the battery cable. Should yellow wire connect with battery cable on the same terminal or use the medium terminal?

[DaveInCanada]

@Billhanlon I'm working with the original wiring harness. It was removed when I got the car and so I have re-run it. I've got the ignition switch connected (it's a multi-pronged plug) and have traced most the wires. The pink wire is messing me up a bit. According to the diagram, I think the pink wire from the ignition switch is supposed to connect to the junction (in my pic) but it's connecting to the transmission switch thing on steering column.

[Bill Hanlon]

Looked in the wiring diagram and found the terminal block that you posted a picture of.

[DaveInCanada]

So it looks like the battery cable and yellow cable should be on the same terminal. is that right? It also looks like there is a ground wire on the "S" terminal as well.

[Bill Hanlon]

Originally Posted by DaveInCanada

@Billhanlon I'm working with the original wiring harness. It was removed when I got the car and so I have re-run it. I've got the ignition switch connected (it's a multi-pronged plug) and have traced most the wires. The pink wire is messing me up a bit. According to the diagram, I think the pink wire from the ignition switch is supposed to connect to the junction (in my pic) but it's connecting to the transmission switch thing on steering column.

Assuming an automatic transmission (which the wiring diagram doesn't) the pink wire going from the ignition switch "sol" to the "transmission switch thing" should continue from another terminal on the "transmission switch thing" through the junction previously discussed to the "S" terminal on the starter solenoid. The "transmission switch thing" is what only allows starting the motor while the transmission is in Park or Neutral.

[DaveInCanada]

Correct. The yellow goes into the trans switch, while the purple wire goes out to the "s" terminal of the starter. So looks like that is good. yes, it's an auto trans. Now I need to know if the yellow wire connects to the same terminal as the battery cable.

[Bill Hanlon]

Originally Posted by DaveInCanada

So it looks like the battery cable and yellow cable should be on the same terminal. is that right?

Yes, the large terminal on the solenoid.

Originally Posted by DaveInCanada

It also looks like there is a ground wire on the "S" terminal as well.

No ground on the "S" TERMINAL. If you are talking about the ground shown on the left side of the solenoid, that is frame ground for the solenoid. Basically just metal on metal from the solenoid case to the starter case.