Another Power Inverter

[John/CT]

I know there have been quite a few threads about Power Inverters and here’s another one. A friend recently purchased a ’30 Pickup from Pennsylvania with the pictured inverter bolted under the seat. Unfortunately the wires were cut and we can’t find wiring instructions anywhere on the Web. It is curious that the three power conversion options listed on the label do not include 6v positive ground to 12v negative ground as would be required to use some modern auto electrical accessories on a Model A. However, the unit was permanently installed and, presumably, working. Has anyone seen one like this, and, better yet, help with wiring instructions?
Thanks, John

 

[MrTube]

The ground isn't relevant as long as the case isn't hot (connected to negative in the device).

The only difference is you run the + to the chassis of the car instead of the -.

If the case/housing is connected to the negative you'll need to insulate it from the car. You can check with an ohm meter to see if you have near 0 ohms between negative and the case/housing.