What is this?

Rockbass

Junior Member
Hi All,
The car is 1947 ford sedan mostly original. This part is under the dash on the upper left corner of the firewall. It has no visible wires attached. I would like to know what it is before I take it out. Thanks for your help. Brian
 

Attachments

  • 20E6EA7C-10FD-4796-95A9-7D7B3087B062.jpeg
    20E6EA7C-10FD-4796-95A9-7D7B3087B062.jpeg
    124.4 KB · Views: 403
It's the circuit breaker/resistor board. The resistor steps down the voltage to the coil and the circuit breaker takes the place of a fuse for your lights etc.....

428920
 
Last edited:
Yes, ballast resistor and circuit breakers. On a 47 there should be two circuit breakers inside the enclosure, both for the lighting circuits. If it is not connected there must be some major wiring changes. I would guess an added fuse panel and a "can" style coil in place of the original coil. Is it 6v or 12v? Positive ground or negative ground?
 

Attachments

  • Flathead_Electrical_wiring1946-48car.jpg
    Flathead_Electrical_wiring1946-48car.jpg
    93.9 KB · Views: 12
re the resistor: Original resistors are available. Those pieces were quite robust, no moving parts, just a big resistor. Most originals still function perfectly well. A few years ago when I thought (wrongly) that I needed one, VanPelt had a stock of them. I would guess that others who deal in original parts do too.
 
Thanks for your replies. I took it out and there was in fact no wires attached to it.
I took a picture of where those heavy gauge yellow wires go to. They are attached to a brown rectangular terminal block which is screwed onto the backside of the gauge cluster panel.
Is this an after market solid state circuit breaker?
 

Attachments

  • 77496161-5084-4F62-A893-20B8F3A2ED3A.jpg
    77496161-5084-4F62-A893-20B8F3A2ED3A.jpg
    59.6 KB · Views: 291
Yes, it runs just fine with all electrical components okay. It’s original 6 volt positive ground. Just want to know what I’ve got.
 
Thanks for your replies. I took it out and there was in fact no wires attached to it.
I took a picture of where those heavy gauge yellow wires go to. They are attached to a brown rectangular terminal block which is screwed onto the backside of the gauge cluster panel.
Is this an after market solid state circuit breaker?
428976


What's on the other side of those connections???
 
I've seen that setup before, it is similar to the 48-49 truck wiring. The first photo is labled as a 47. The device shown is the circuit breakers (2) and a resistor is not needed with the can coil.
 

Attachments

  • 1947 Yellow wire to ammeter.jpg
    1947 Yellow wire to ammeter.jpg
    74.3 KB · Views: 199
  • Flathead_Electrical_wiring1948-49truck.jpg
    Flathead_Electrical_wiring1948-49truck.jpg
    95.3 KB · Views: 15
Last edited:
I have the same set up as Rockbass with the resistor attached to the original coil under the hood. The dash set up consists of a junction block with circuit breaker. This is a 6v + ground system, late '47 (Nov) super deluxe 4 door sedan.
Could this be one of Ford's "running changes"!!??
 
JSeery, I think you nailed it, thanks for sharing your knowledge. Wow, what a great resource this Fordbarn forum is. Oh, one more quick question, what is a “can” style coil?
Brian
 
Back
Top