Wiring, 1 at a time...

[maine48ply]

So, I have decided to rewire my '48 Special Deluxe, 1 wire at a time. Its much more affordable and will be a great learning process.

I have not been able to find a definitive source of information that tells me the gauge of each individual wire. Does such a source exist? The wiring currently on the car is too worn to recognize any color codes that may have been there.

Any help will be appreciated.

[Young Ed]

I based mine on the 49 chart as found in the 46-54 shop manual. And I replaced all 16g with 14

[greg g]

Search wiring diagram. there is a post (I think from BobT) that has a p15 schematic with the gauges posted, but rule of thumb is heavy load 10 gauge (headlamps, heater,horns) to circuit breaker.

medium load, 12 gauge,(runing lights, signals, stop,genny to regulator) and light load, int lights, ign. dash lights, 14 gauge

[maine48ply]

Thanks fella's, it didn't even occur to me to look at the other wiring diagrams in the manual. It seems that the P15 is the only one where the gauge sizes are not listed. Problem solved. And, I WILL replace the 16g with 14g, as suggested.

[greg g]

Good rule for 6 v systems, when in doubt go bigger. Don't forget to attend to your grounds. Also adding a ground strap from the body to the frame or engine is a good idea.

[Bobtjr(dale)]

This is what i did to my fathernlaws 47 p15.

Before I took the wiring harness out of the car I labeled each wire eactly where it goes.

Then I unhooked eveything, pulled the entire harness out of the car.

Then I laid it out on the shop floor and started rebuilding the wire harness one wire at a time retagging each wire as I tagged the original . When your done you should have two wiring harnesses, identical in length and shape. Both tagged and the new one ready to reinstall.

As far as wire color either you can draw out a color diagram yourself, or use one color of wire because you tagged both ends of the wire.

By the way if you take clear box tape and encase your tags they will be readable for years to come. They will be water proof and grease proof. Also the ink can't run.

Also its a good idea to put the old one with the tags still in place in a bag or box in storage, so you can have a reference for latter if you ever need it.

I used one color because of expense.

His harness has been in the car and worked flawlessly since 1992

ps. Make shure you flux all your wires before soldering. A cold solder can be difference between failure and success.

OH, by the way pay attention to the guage of wire you use, you can make it out heavier guage, but don't go to lighter guage. The wire can over heat.

Hope this helps Dale

[Bobtjr(dale)]

Good rule for 6 v systems, when in doubt go bigger. Don't forget to attend to your grounds. Also adding a ground strap from the body to the frame or engine is a good idea.

yes, I totally agree, every one on these cars I have seen has not had a ground strap between the motor and body or frame.

It helped my amp guage to read correctly

thanks again Dale

[Bobtjr(dale)]

This is what i did to my fathernlaws 47 p15.

Before I took the wiring harness out of the car I labeled each wire eactly where it goes.

Then I unhooked eveything, pulled the entire harness out of the car.

Then I laid it out on the shop floor and started rebuilding the wire harness one wire at a time retagging each wire as I tagged the original . When your done you should have two wiring harnesses, identical in length and shape. Both tagged and the new one ready to reinstall.

As far as wire color either you can draw out a color diagram yourself, or use one color of wire because you tagged both ends of the wire.

By the way if you take clear box tape and encase your tags they will be readable for years to come. They will be water proof and grease proof. Also the ink can't run.

Also its a good idea to put the old one with the tags still in place in a bag or box in storage, so you can have a reference for latter if you ever need it.

I used one color because of expense.

His harness has been in the car and worked flawlessly since 1992

ps. Make shure you flux all your wires before soldering. A cold solder can be difference between failure and success.

OH, by the way pay attention to the guage of wire you use, you can make it out heavier guage, but don't go to lighter guage. The wire can over heat.

Hope this helps Dale

Hey, I hope this does not sound to elementary I was not trying to talk down to anyone!

Dale

[Jim Saraceno]

[Robert Horne]

Search wiring diagram. there is a post (I think from BobT) that has a p15 schematic with the gauges posted, but rule of thumb is heavy load 10 gauge (headlamps, heater,horns) to circuit breaker.

medium load, 12 gauge,(runing lights, signals, stop,genny to regulator) and light load, int lights, ign. dash lights, 14 gauge

I used these numbers also with my 38, 12 volt system. I used a fuse box from a Nissan. Have plenty of extra fuse connections, if I want to add anything extra, like power outlets in the trunk, or extra lights, coffee pot, refrigerater, etc.

[boxer_inv]

Hi there

It's not too long since i finished my 47 D24 rewiring project and I was in the same boat as you - wiring too old to see the colour and disintegrated when touched.

If you run a quick search "rewiring" you'll see a few of my threads come up - plenty of photos and more importantly, plenty of really good advice from the other members too.

http://www430.pair.com/p15d24/mopar_forum/showthread.php?t=17534&highlight=rewiring

http://www430.pair.com/p15d24/mopar_forum/showthread.php?t=18025&highlight=rewiring

I actually ended up using a combination of wiring schematics to do mine - the one from my original manual, another one from a 'twin sister' P15 manual that was supplied by members, and yet another one (which has already been posted on this thread) which indicated the gauge wire.

I printed out copies of these and used them for reference at every turn during the project - check and re-check everything! Even then after install I had some gremlins to overcome - but all good now!

I ended up making my own colour coded wiring diagram in MSExcel - happy to email you a copy of this if you want - you might make changes to it to reflect your own project.

Regards

Aussie Rob.

[maine48ply]

Aussie Rob.....I would love to see the color coded diagram you created. You can email to mbilyk@roadrunner.com

By the way, even though I currently reside in Maine, USA, the 1st 2 years of my life were spent in Melbourne. I hope to go down again one day.

Also, could someone please explain the ground strap that has been mentioned. I am assuming that I don't have one as a stock item?

[pflaming]

Ground strap: The bed (truck), the body, and the front fenders are all in some way NOT metally connected to the frame. The cab is on rubber bushings/bumpers, the bed has wood between it and the frame and the fenders, I'm not certain.

SO a ground strap is a brace or a wire that connects these to the frame and thus lets the current "ciruculate" back to the battery (the frame is, in effect, a huge wire that takes completes all circuits). On old vehicals these connections worsen. SO . . . I (and others) have taken a # 10 wire and connected it to the frame and to body, the gas tank, etc and that will ensure your vehical is grounded. Fought this for a full day until someone explained it to me in layman's terms.

Good luck.

[maine48ply]

Thank you, ground strap can now be a part of my ever expanding vocabulary.

[Don Coatney]

Hey, I hope this does not sound to elementary I was not trying to talk down to anyone!

Dale

Hey punk! Dont talk down to me again or I will squich your pops harmonica.

Here is my ground strap.

[greg g]

Jim, the wire schematic the you posted shows a diagram for a V8, battery looks like a 6V with three cells but thse gauges look light to me, I would go up a gauge on each application.

[Jerry Roberts]

I also used a ground strap like Don C's . Mine goes between the body and the frame . Purchased at the local auto parts store .

[Bobtjr(dale)]

Hey punk! Dont talk down to me again or I will squich your pops harmonica.

Here is my ground strap.

Don your the loving mentor I have always wanted in my life

jr:p

[pflaming]

Don, your strap goes from the engine to the frame. I have such a strap, didn't know what it was. Why is the strap used as opposed to a wire or cable. It is so that it has in effect 360 degree flexing and thus lasts a long time? Would you use the same strap from the bed of a truck to the frame? I used a #10 wire and it works, will it last may then be the next question.

[Don Coatney]

Don, your strap goes from the engine to the frame. I have such a strap, didn't know what it was. Why is the strap used as opposed to a wire or cable. It is so that it has in effect 360 degree flexing and thus lasts a long time? Would you use the same strap from the bed of a truck to the frame? I used a #10 wire and it works, will it last may then be the next question.

I am really not sure why a strap is used as opposed to a wire. But a strap has been the standard for this application for many years. On the machines I am upgraqding for the Federal Reserve Banks a new strap is icluded in the parts and must be installed in a coule of applications.

[martybose]

When I had my custom ground cable made I had them add a couple of pigtails so that my ground cable goes from the battery to the starter mounting bolt, the cab and the chassis at the clutch pivot bolt. I figure that should cover all of the ground issues!

Marty

[pflaming]

Don: Been thinking about your comment. The braided make-up of the strap makes it very flexible. We have both been involved with mechanical work and grounding is so critical. With all those wires I would think a braided strap is almost indestructable thus it provides GREAT protection.

On a car or truck the twisting / flexing that occurs between body, engine, etc. and frame is endless and varied so the braid is the best answer for long term grounding. Such is my conclusion and I am going to use the one I have at the engine for certain. At the bed originally it has a flat iron strap on each side. Haven't found the ground from the cab, but there must be one.

Always appreciate your insight and knowledge. I wish you safe traveling in your job. If you get close to Fresno, call, dinner or coffee on me.

Paul