1964 Plymouth Valiant Wiring Harness Build/ Questions

[kiyoshi]

Hello everyone,

I'm currently rebuilding a engine side wiring harness for a 1964 Plymouth Valiant and just had a couple of questions and wanted to take some advice and insight from those more knowledgeable than I am.

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Products Used:​

-Milspec M22759/16 wiring

-TechFlex Insultherm braided shielding

-Tessa Tape 51036

-Permatex Liquid Electrical Tape

-3m high temp ring terminals used where it was possible

-rest are tin coated brass terminals

Tools:
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-Klein Tool Open Barrel Crimper

-Klein Ratcheting Crimper

-Irwin Wire Stripper

-No name wire stripper

-No name wire cutters

Harness Layout:
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10 gauge black - alternator ring
16 gauge green - alternator packard 56 1 pin
16 gauge purple - coolant temp sensor
12 gauge blue - coil wire to resistor
12-12 gauge blue / brown - double resistor connector top
14-16 gauge blue / blue - double resistor connector bottom
** gauge blue - ignition relay top
16 gauge green - ignition relay bottom

(I need to double check these gauges but I think these are what I used)

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I had a few questions regarding the safety of the harness and just wanted some insight if anybody has any. My concerns are the following:

The starter harness of only two wires used to loop from the starter relay all the way around the front of the block and then back down towards the firewall. I thought this was ridiculous and an unnecessary path. I shortened it to go directly from the starter relay to the starter. Additionally, the wires that were originally there were already replaced with something not stock. Best I could measure, the black wire (OEM red and since chanced to red) was a 10 gauge wire, and the brown THAT WAS THERE ORIGINALLY was falling between a 10 and 12. 12 was a little bit too tight and it fell easily out of the 10 gauge in my wire gauge measuring tool, and the black 10 was definitely a 10 gauge without doubt.

Because of this, I did a little digging in the forums. Again, best I could find, people are saying you should be running AT LEAST a 10 gauge red wire from the starter, and at LEAST a 12 gauge wire for the smaller diameter brown wire. There are some saying they step up to a 8 gauge red and 10 gauge brown. PLEASE let me know your thoughts.

Additionally I think I'm keeping the ammeter for now, and if I am, this small harness is NOT where I would want to put a larger fuse correct? I would want that between the small 10gauge red wire that connects from the starter relay lower ring terminal to the firewall connector? I ask about this routing specifically as it is what Painless is listing in their Mopar 21circuit custom harness installation instructions. Again just wanting to confirm.

-kiyoshi

 

[kiyoshi]

ANOTHER POINT OF CONCERN AND MORE INFORMATION:

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----------------------CURRENT NEW STARTER HARNESS----------------------
-10 gauge red - starter wiring to lower relay ring terminal
-12 gauge brown - smaller starter post to starter relay left side spade terminal


-----------------CURRENT NEW SECONDARY HARNESS-----------------
I was reading the Painless harness instructions and some others that had rewired and were saying to step up the size of the yellow wire from the starter relay to the firewall connector? Is this safe to step up even though the connecting side that continues behind the dash is not the same size? It is a stock OEM size of 16 gauge and I upped it to 12 gauge for that small run. Again let me know. Also also, I need to remake the red/purple, but would this be where I am putting a larger amp fuse?
-12 gauge yellow - starter relay to firewall connector
-12 gauge purple - starter relay to horn bottom
-12 gauge red - starter relay to firewall
-16 gauge black - firewall connector to horn relay top

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OK SO NOW MY MAIN WORRY BEFORE I CONTINUE

I'm seeing people install a fuse for the ammeter (/issue) and I was looking in to what amp fuse to get correct? Again pairing information regarding those that were either running a 10 gauge or upped 8 gauge red wire. I want to say I was seeing information and electric wire gauge charts that people were listing and were saying that if you're running a 10 gauge wire, to run anywhere between a 50-60 amp fuse between the red wire lower ring connector at the starter relay to firewall connector, also listing that if you run a larger 8 gauge wire that you can bump that up to something the likes of a 70-80 amp fuse.

MY WORRY IS even though the wiring I purchased I believed to be a far superior quality than that of a standard gxl automotive wire, I was looking in to the AMPERAGE ratings and was getting worried. Everything I can find lists it as around 30-32 amp current rating based on continuous duty for wires in bundles, harnesses, or conduit at sea level. Some lists I'm seeing is listing this at a max of 23 feet... is this something I should be worried about?

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I look forward to any tips, pointers, or even anybody I should message directly. I'll keep looking in to the electrical sections of the forums in the mean time but please let me know your thoughts on 4 things:

1. The location of where the fuse should go for the ammeter
2. What amp rating fuse should I use
3. Is the 10 gauge red wiring I'm using for the starter harness as well as the small red from starter relay to firewall harness connector going to be ok you think? Any information you can back it up with?
4. Just in general, do these wiring sizes look right? I've done DAYS worth of research and constantly keep checking and exploring new places of information, I'm just again a bit on the spectrum which in turn makes me definitely overthink and over worry but at the same time, I know I get distracted and kinda have to find this happy medium of telling myself it's ok but also telling myself to pay the heck attention.

I think I upgraded the size of the blue coil wire but possibly not I'll have to double check, the yellow wire listed, and I believe that is it. That and sized the brown starter wire to 12 instead of whatever weird maybe 11 gauge possibly not good automotive wire that it was.

-kiyoshi

 

[kiyoshi]

Rest of the harness photos for now:

 

[kiyoshi]

Any ideas?

-kiyoshi

 

[67Dart273]

I am not familiar with the early cars, but I would certainly carefully consider upsizing many of the wires. If you are using absolutely stock wiring diagram scheme, even so I would consider adding some fuses and or relays. Voltage drop in the bulkhead connector, ammeter circuit, ignition and headlight / dimmer switch is some of the "big."

 

[kiyoshi]

I am not familiar with the early cars, but I would certainly carefully consider upsizing many of the wires. If you are using absolutely stock wiring diagram scheme, even so I would consider adding some fuses and or relays. Voltage drop in the bulkhead connector, ammeter circuit, ignition and headlight / dimmer switch is some of the "big."

That's why I'm asking lol. I'm not up-sizing many but rather just what was listed so still looking for some input

Fuse wise I'm gonna be tackling that when I get to the under dash harness where the stock fusebox is located

I was seeing some of the issues you were mentioning regarding dim headlights etc in some of the other threads but that's a different portion of the harness for now. I guess the "headlight harness" in comparison to the engine bay (yet again another harness to tackle eventually lol)

Still looking for some input but most likely going to just move forward with the project. On a side note though, been working around at a shop and they/we got a new old toy! Woo Tormach

-kiyoshi