Headlight Junction Block

[50 coupe]

Redoing the wiring to the headlights and turn signals this weekend. Got to wondering, what exactly is the purpose/function for the junction block? Is it merely a place to anchor the wires on a long run or is there another purpose? Could the wires not be run directly between the lights and switches without it? Just curious.
 

 

[Plymouthy Adams]

it makes for easy disassembly of the front metal when removing a doghouse for maintenance

[desoto1939]

The junction box is purpose is a connection point basically from your dimmer switch with the wires to control the high and low beam lights and there is also on some cars the parking lights connection on the junction block.

 

On the lights since you have a pair for th3 eheadlights this permitted the car manufacturers to  have someone make the individual wire harness for each light and then when on the assembly line the individual headlight could be wired and the line then run back to the junction block.

 

You could eliminate the block if you want to.

 

Rich Hartung

[DonaldSmith]

I think the primary purpose of junction blocks was for sub-assembly of the car.

 

I'm sure that Briggs had the body pre-wired, especially considering that the wires to the rear were run behind the headliner.

 

I'm guessing that the dash was a separate assembly (installed by Briggs or by Chrysler?).

 

Then came the chassis with engine, and the doghouse, on the Chrysler assembly line.  

[Tom Skinner]

Dennis Bickford has replacements:

Headlight Junction Boxs (Replicas - Like the Originals)

Vintage Woodworks

PO BOX 1132

LaLuz, NM. 88337

Phone (575) 443-1160

Dennis is a very honest honorable Gentleman, he ships you your stuff first

then you pay -- his business is built upon trustworthy people. He is first and foremost the best there is.

Dennis has been around for decades and is an absolute credit to this hobby.

Tom Skinner

Huntersville, North Carolina

[50 coupe]

OK, thanks for the info. I cleaned up my original junction block and will be using it. I see were it is useful for joining wires to different circuits also. This is my first wiring rodeo so learning as I go.

Edited March 29, 2016 by 50 coupe

[rb1949]

Good project. Are you using similar color codes via a diagram? Working with behind dash connections seems to be a challenging tight fit. I'm about ready to attempt replacing wires to the rear. First estimate measurements, make a long protected harness (5 wires?), and attach it to the frame going back. Want to use a junction block in the trunk. Save a day for the actual hookup.

edit: whoops, I counted 8 wires to the rear, not 5. Are you using 16GA wire?

Edited March 30, 2016 by rb1949

[50 coupe]

Good project. Are you using similar color codes via a diagram? Working with behind dash connections seems to be a challenging tight fit. I'm about ready to attempt replacing wires to the rear. First estimate measurements, make a long protected harness (5 wires?), and attach it to the frame going back. Want to use a junction block in the trunk. Save a day for the actual hookup.

edit: whoops, I counted 8 wires to the rear, not 5. Are you using 16GA wire?

Sorry for the late response, using 14 ga where the book called for 16ga and using 10,12,8 where called for. doing each wire at a time and referencing the wiring diagram. A PO on this car did some shade-tree wiring at some point. Found  lamp cord used in some places among other things...... I have access to 'free' wire so not matching the color coding. The existing wiring is so faded I can't tell which is which on there now other than tracing each one.

 

Going to try using a release button type brake light switch versus the in line switch. 

Edited April 19, 2016 by 50 coupe

[rb1949]

True, can't tell what colors those nasty old wires are. Tracing one by one is necessary, and wild where they go. And not an inch of slack. Pull out a switch, yet you can't move it far enough to see anything. There's room, I'm going to add plenty of slack in the wires. I found a 2 wire junction screwed to the 'box' that holds the ashtray. Ha. No restoring to original here, I want things to work. "There's more than corn, in Indiana." Keep updating your adventure.