I'm restoring a 1955 Studebaker President and it has an electric component I also seen in other 50's cars, but don't know what is it for. It is similar to this stuff, right now it is disconnected...

enter image description here

So what's its purpose? How is it called?

  • 3
    Hey Aram! The answers below have it correct. This is a solenoid, most likely attached to the starter. If you are looking for a replacement, Ford had used them in almost everything from the 80's and before. They look pretty much like your picture, only they have a 4-pole, where I think the second small pole is used for full voltage relay out to the ignition system during startups. It would still work for you here. Commented Aug 26, 2022 at 15:24
  • Thank you Paul. The engine is not the Studebaker v8, and it has a much modern starter with incorporated solenoid, so I guess I don't need to hook this thing on, correct? Commented Aug 26, 2022 at 16:23
  • 2
    If the engine you're using has a starter which is incorporated, you won't need this. Commented Aug 26, 2022 at 16:52

3 Answers 3


Looks like a 3 terminal relay (or isolation solenoid). The metal frame is Ground. The large lugs are Battery IN, Battery OUT and the small lug is for RUN or possibly CRANK.

Not sure what they are used for in older cars but I use a 4 terminal one in my VAN for isolating the batteries that run a power inverter. Like what's imaged below. enter image description here


This is a universal heavy-duty solenoid, used for starters and other low-voltage, high-amperage applications.(*)

Manufacturers include Grote, Cole-Hersee, and Standard Motor Products.

The solenoid in your Studebaker probably was used for the starter at one time, and if it's disconnected now it can be removed.

This is beyond the question, but note these types of heavy-duty solenoids are generally not safe for electronics, and a flyback diode must be used on the coil circuit (unless a diode is specifically built into the solenoid).(*)

*Source: firsthand fleet experience.


Looks like a starter solenoid https://en.wikipedia.org/wiki/Starter_solenoid Example https://www.amazon.com/dp/B09B7YTFW2/

  • 3
    Your answer could be improved with additional supporting information. Please edit to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers in the help center.
    – Community Bot
    Commented Aug 26, 2022 at 14:27

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .