'54 Commander - How do the start switch and solenoid work?

[Flashback]

Is your solenoid a metal body one? Yes? Don't do nothing. My 53 works just fine. I used a 53 solenoid and a auto trans 53 toggle. The def and heater motors can be replaced with Mustang 65-66 blower motors.
Here's the solenoid. Is this like yours?


Here's the def motor (sorry bad shot) It's looks like it belongs

[Dick Steinkamp]

I wonder if you could use the stock 6V solenoid and just get your full 12V for starting off the big terminal on the starter side of the solenoid?

[RadioRoy]

I just rewired the starter switch on my 54 when changing to 12 volts. It was pretty easy to remove the ground connection as I recall. It was not internal, but was an external solder joint to the case. This was 30 years ago, so my memory may be fuzzy, but it was pretty easy.

[northern]

It sounds as if there is more than one way to skin this cat. The car seemed to work fine before starting on the total rewire of the car, so, as several people suggested, it might make sense to stick with the same configuration with the new wiring and at least try it more to see whether problems occur. Right now, I'm part way through the rewire and testing things as the job moves along.

Someone asked about the solenoid on the car. It is a metal body three wire solenoid, likely from a six volt system positive ground system, and it bolts to the inner fender near the battery. The voltage to the coil feeds from a separate circuit and is reduced by the ceramic reducer on the firewall.

Fusing the main wires certainly is a good idea. The new harness included a 14 gauge fusible link that went into the 10 gauge battery wire that feeds the harness. I plan to add another fusible link to the 10 gauge wire that runs from the solenoid battery terminal to the ammeter. The fusible links, along with all the fuses in the new panel, should protect the system.

And thanks for the tips on the heater/defroster motors. A seller on ebay had a '57 defroster unit, which I bought and am waiting for. So far I haven't been able to find a second one for the heater. As suggested, a Mustang unit might be the answer for the heater motor.

Rewiring a car with a non-original harness is a good mental exercise. Today, I spent several (or more) hours making sense of the steering column, signal light, and brake wiring. To complicate matters, the replacement harness had a "factory error" that took a while to find.

[MPallock]

A similar fix to what Studerich is talking about. When I converted my 54 to 12 volts I wanted to keep the original toggle start switch. So I removed from the dash and used a Dremel tool to cut the tab on the switch that goes to ground. Now I have single pole single throw switch. Put 12 volts on one side. the other side to the neutral safety switch then to the single terminal on the solenoid.

[Boothguy]

A similar fix to what Studerich is talking about. When I converted my 54 to 12 volts I wanted to keep the original toggle start switch. So I removed from the dash and used a Dremel tool to cut the tab on the switch that goes to ground. Now I have single pole single throw switch. Put 12 volts on one side. the other side to the neutral safety switch then to the single terminal on the solenoid.

Now we have the definitive answer

[northern]

A similar fix to what Studerich is talking about. When I converted my 54 to 12 volts I wanted to keep the original toggle start switch. So I removed from the dash and used a Dremel tool to cut the tab on the switch that goes to ground. Now I have single pole single throw switch. Put 12 volts on one side. the other side to the neutral safety switch then to the single terminal on the solenoid.

Not sure how that would work. The (presumably original) switch in my car only has one terminal, not two. Moving the switch grounds the hot wire to the car ground. If one isolates the switch body from the car body, moving the switch won't do anything. One would have to modify the switch somehow to add a second terminal.

[RadioRoy]

Not sure how that would work. The (presumably original) switch in my car only has one terminal, not two. Moving the switch grounds the hot wire to the car ground. If one isolates the switch body from the car body, moving the switch won't do anything. One would have to modify the switch somehow to add a second terminal.

I think the key here is that the ground connection on the starter switch is NOT internal to the switch. You can actually see it on the rear of the switch. If you disconnect the ground connection and connect the remaining tab to +12 volts, the switch will provide +12 volts to the solenoid.

Again, I am going from memory, but it seems as if the ground connection to the switch case was obvious from looking at it and it was not difficult to disconnect that ground connection, and then connect it to +12 volts.

Maybe there are two different versions of the switch and yours is not like the ones the rest of us have described.

[leyrret]

There are many variations of these starter solenoids. They make look similar or identical but the internal wiring may be different. Your solenoid has the operating coil internally fed off the bat terminal and grounded using the small terminal. NAPA 6v#-ST53, 12v#-ST56 , Cole Hearse 12v#- 24115(metal),24077(plastic)

[MPallock]

I think the key here is that the ground connection on the starter switch is NOT internal to the switch. You can actually see it on the rear of the switch. If you disconnect the ground connection and connect the remaining tab to +12 volts, the switch will provide +12 volts to the solenoid.

Again, I am going from memory, but it seems as if the ground connection to the switch case was obvious from looking at it and it was not difficult to disconnect that ground connection, and then connect it to +12 volts.

Maybe there are two different versions of the switch and yours is not like the ones the rest of us have described.

RadioRoy is correct

Mark

[leyrret]

4 pole starter solinoid... NAPA number ECH ST81.. $23.20. Just bought one last week.

Wanted to add ST 81 is external fed coil with internal ground. The fourth terminal is ignition resistor by pass. There are many 4 terminal that have isolated coil(feed through one small terminal and grounded with the other with no resistor bypass. There are also five terminal with isolated coil and resistor bypass. You can find one to accommodate just about any way you desire to wire it.

[DEEPNHOCK]

Great thread.
Good header.
Quality info for now and in the future.

[Flashback]

Simply puT: Your solenoid grounds to activate, if it is original. Your toggle is a one terminal normally open. It grounds when toggled. A wire from switch to small terminal on solenoid. Bingo, No high tech