Junction Box

Davew

Davew

Senior Member
New owner of a 1930 coupe. I have been trying to figure out the junction box wiring but have not been able to find a picture of one that is open. Mine did not have a cover on it so wires are visible. Would like to put it back right. Tried to enclose picture of mine
Thanks, David
 

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David-
I can help you with this faster over the phone than I can by typing a long reply. Shoot me an email at tech@mafca.com or send my a Ford Barn Private Message and I will send you my phone number.

You are missing more than just the cover. I can help you. Not a big deal.
 
A PM doesn't help the rest of us.
The only two wires on the passenger side should be the one from the starter and one to the ammeter. All others including the coil should be on the drivers side.
 
The most important thing about that junction box is that nothing is shorted out. Quarters are close in there and from the photo it looks to me like one of the terminals is or is about to short to the speedo cable.

Tom Endy
 
Attached electrical sketch shows the connections at the terminal box. Note that the ammeter leads straddle the terminal. The wire from the coil can go on either side. The wiring in the early cars had it connected to the opposite side. It was later changed to the other side so that ignition current will flow through the ammeter. This provides a diagnostic tool. When starting the car the opening and closing of the ignition points will register on the ammeter. If the car doesn't start and the needle in the ammeter is waging back and forth it tells you that the primary side of the ignition is working and that the problem is elsewhere.

Tom Endy
 

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Does any one have a picture of their junction box with the cover off? I'd like to see it. One of the cables running in there is a water temp wire. The ignition cable is what got me wondering what to do. Jim, I sent you a pm. Thanks
 
There's nothing complex or sophisticated about it. It's just a couple of handy, isolated bolts that allow you to conveniently tie together some wires that need to be connected.
 
Hi David,
Once you got it sorted, the vendors supply loose covers as well as repo wing nuts.
Enjoy your Model A.
 
thanks for the replys. I have ordered a new box with cover. with the diagram and some luck maybe i can get this right. David
 
There should be a rubber grommet on the ignition cable where it passes through
the junction box.

Bob
 

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Here is a picture.

I added the wire loom cover to the shielded wire from the ignition switch to the distributor. I don't have a pop-out.

I also have the water temperature gauge wire running through the center..


.
 

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Tom Endy said:
The most important thing about that junction box is that nothing is shorted out. Quarters are close in there and from the photo it looks to me like one of the terminals is or is about to short to the speedo cable.

Tom Endy
Click to expand...

Hmmm. Speedo cable in the junction box?? :confused::confused:
 
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Bob C said:
There should be a rubber grommet on the ignition cable where it passes through
the junction box.

Bob
Click to expand...

I always had to split mine lengthwise, another aspect of having neoprene rather than original rubber parts
 
isn't there often some contradiction in the restoration books about the yellow vs. the yellow w/tracer wire; that they can be safely reversed within the entire wiring system?
 
When you get your new junction box, make sure that the heads of the two wing-nut bolts do not project beyond the back of the case so there is a risk of shorting out to the firewall. This was a problem with early repro boxes, due to use of round-head bolts with inadequate recess. If in doubt, you could put a few strips of electrician tape or other insulator over them, just to be sure.
 
Quote:
Originally Posted by Tom Endy View Post
The most important thing about that junction box is that nothing is shorted out. Quarters are close in there and from the photo it looks to me like one of the terminals is or is about to short to the speedo cable.

Tom Endy

1955cj5 said:
Might that be the shielded ignition cable from the pop out switch?
Click to expand...

I would have to agree, it sure isn't the speedo cable. :rolleyes::rolleyes:
 
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steve s said:
When you get your new junction box, make sure that the heads of the two wing-nut bolts do not project beyond the back of the case so there is a risk of shorting out to the firewall. This was a problem with early repro boxes, due to use of round-head bolts with inadequate recess. If in doubt, you could put a few strips of electrician tape or other insulator over them, just to be sure.
Click to expand...

Could snug up the screws and nuts then backfill the screw heads with epoxy or jb weld. No way to short out then.
 
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