Old cable/ harness old

[BayArea48Deluxe]

Howdy gents I have a 48 Dodge Custom, I have examined my harness and my cables are old and crumbling and I’m looking to replace them. I have old original wiring harness I’m sure. I don’t truly wanna buy a harness already made so I’m most likely making my own. So what gauge are these old wires I don’t see any markings . How many ? I noticed two different ones if I’m correct. Ome from the motor compartment and one runs off towards the rear . Any help

appreciated. 
thanks in advanced . Fredo 

[Jerry Roberts]

Some of the shop manuals for these old cars have wireing diagrams that show the wire gauge . If you don't have a shop manual for your car you might shop for one that shows this information . Also search old posts here that have covered his information. It is not hard to rewire your car doing just one wire at a time so that you can keep track . 

[DonaldSmith]

Something from some time ago: Wiring gauges    2005, 01/28   greg g gonyagl@morrisville.edu (old?) 

 

signals parkt 16                                   genny field 16                         dimmer switch power in 12               tail stop 16

headlights 14 low        12 hi                        amp 10                                      load out 14                                          fuel 16 ground 

                                                      regulator bat 10                      to indicator light 16                            cigar lighter 12

horn 10                                                  ign to solenoid 10                  coil 14 both                                         heater motor 12

Looks like most interior lights are 16, motors 12, high draw 10.

 

[BayArea48Deluxe]

I do have the shop manual and I was looking at the diagram and I didn’t see any wire gauge either .. hmmm interesting 

[BayArea48Deluxe]

And yea when I was looking at the harness I was imagining like most of it was 14Awg just to sight . And yea also just going on site like 2 looked like 10 Gauge and then two others ones were a little thicker. Yea I was having trouble removing my Gauge cluster to get to the harness comfortably…

[Sam Buchanan]

In the course of rewiring the headlights on my P15 with relays and fuses I found the original wire that was still under the cable wrap was in excellent condition. Only the cloth insulation on wires that protruded from the cable wrap had weathered and deteriorated. So if enough cable wrap is removed to reveal good insulation then shrink wrap can be installed over the frayed areas and the harness will be in serviceable condition so that complete replacement may not be needed.

 

I used 12g for the headlight circuits, it appears that is the gauge for the high beams and 14g was original for low beams.

[Young Ed]

The original wire had black markings on it to dictate gauge. You might be able to read them under the wrap. Beyond that for my 48 I used the 46-48 diagram for connections and the 49 diagram for wire size. In my 46-54 shop manual only the 49-54 diagrams list gauge. I also upgraded all the 16 in the car to 14

[Conn47D24]

Rhode Island Wiring

 

Worth it

[Eneto-55]

On 8/11/2024 at 6:42 PM, BayArea48Deluxe said:

I do have the shop manual and I was looking at the diagram and I didn’t see any wire gauge either .. hmmm interesting 

As you found, the wiring diagrams in the P15 Service Guides do not have gauges listed.  You can use the diagrams from the new 49 and following models to determine the necessary gauges.  Each wire is also actually marked for gauge by the number of 'tracers' or 'stripes' on the loom.  After 3 stripes, it starts over with none, then goes up again.

 

I have all of that info someplace, and I actually originally got it here on the forum, so it's here, probably in multiple posts.

 

Someone commented about the wire that is still wrapped still being in good condition.  That's how mine was when I started work on the car back in 80-81. At that time I spliced in good wire from a 53 Cranbrook my brother scrapped.  But now it's all brittle. It LOOKS great, until I flex it, even just a bit. Then it starts to crumble. Not safe.  It is "telling" that the Service Manuals that were printed when these cars were only a few years old already say to examine the wiring for frayed insulation. 

[BayArea48Deluxe]

Yea I need to get the space to get back there comfortably because being upside down on my head isn’t exactly the most exciting thing.. I got it off but the harness only allows me to pull it so far so have to do some more digging 

[Young Ed]

If you're going to wire the car I recommend pulling the dash and doing all the wiring on the bench. 

[BayArea48Deluxe]

That’s what I’m trying to do Is have the dash out in space. And I have it off kind off. Off because it is off but still in place and I can’t pull it out as far as I want too. Without clipping the whole harness off. I want to look at it a little better and see if I can maybe cut back far enough and then splice just for now until I’m ready to get into it and get the stuff for it together 

[Eneto-55]

9 hours ago, BayArea48Deluxe said:

That’s what I’m trying to do Is have the dash out in space. And I have it off kind off. Off because it is off but still in place and I can’t pull it out as far as I want too. Without clipping the whole harness off. I want to look at it a little better and see if I can maybe cut back far enough and then splice just for now until I’m ready to get into it and get the stuff for it together 

I originally tagged each wire and terminal, but hadn't planned to leave the car set that way for over 35 years, and the masking tape I had used dried up and fell off. Since I moved the car from Oklahoma to our home here in Ohio and discovered that the wiring is all bad now, I labeled each wire that I could still the old tag with heavy cardboard (not corrugated) and attached the tags with plastic coated twist-ties.  Then I removed the entire harness from the car, and working my way from the front to the rear, I measured each wire to record the exposed length, also marking and measuring to where it passes through the front side panel, the firewall, and at each point where a wire 'breaks out' of the main harness.  My 4-door is a 46, and the harness on the 49 P15 (49 first series) is a bit different. On it, part of the engine harness is separate.  I do still have some wires that I don't know where they go, and a couple of wires under the dash had been replaced before I bought the car (1980), so I still need to find the original gauge and color for them, and where they go. But as I sometimes say, "My work gets in the way of my hobby", so I have made very little progress in the last several years.