[2000jack]

I have a "Supreme Standard " ,"Ford", headlight relay still in the box from around the 40's or 50's with a glass fuse that reads 20 SFE. There is no reference to volts 6 or 12. I would like to use it in my new project, my question is does a relay have a volt size? That is does it make a difference whether it is 6 or 12 volt system?

[gizmo-1948]

If its pre 55, its 6 volt pos. ground--and yes it does make a difference on the voltage. If its 6V and you apply 12V, it will fry the windings on the pull in coil. I would take the number off the box, call your local NAPA store and have them cross reference it to application. They still have older goodies like that available and may be able to help you out with a proper ID.

[2000jack]

Originally Posted by gizmo-1948

If its pre 55, its 6 volt pos. ground--and yes it does make a difference on the voltage. If its 6V and you apply 12V, it will fry the windings on the pull in coil. I would take the number off the box, call your local NAPA store and have them cross reference it to application. They still have older goodies like that available and may be able to help you out with a proper ID.

I know from the box style that it is pre 1955 and it has a little coil inside so I skip it and use a regular relay. Thanks for the help.