About To Replace The Wiring Harness . . .

D Durden

DEEP FAT FRY
Founding Member
Mar 9, 2000
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Okay, I'm about to replace the wiring harness on my '65, and it looks like the Painless wiring harness is the best one to go with. If not, what's better?

I've also heard that the Painless harness doesn't have a lot of the plugs (tail lights and head lights). If not, do any of you guys know what I'll need?

Any other suggestions?

Thanks!!!
 
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I have done a couple of the painless harness ,in a 35 Ford truck and a 48 Ford coupe .Very simple but they do not come with the plugins you will need .Good news is everything is well labeled so at least routing the wires is fairly simple . You could splice in the plugins if you have them ,i would solder the connections, and slip shrink wrap on the wires first . If you go with with the painless harness get the 12 circuit harness, or you could remove the wires from the larger harness but there is a lot of extra wires you will not need .
I have used the new replacement harness .It has the air conditioning wires and i think the heater wires made into the new harness ,a bit confusing at first ,but all the plug ins are there and simply plug in.
 
when it comes to aftermarket wiring harnesses, you have several options these days, all are good, all have the wires marked as to where they go, and most have the option of a prewired fuse block, or one that you wire yourself.

painless is the industry leader, but american autowire is out there as well. one that has fallen from the leader board, mostly because of their price, is ron francis. RF will take a lot of information from you, and build a complete harness ready to install. beware though the last time i priced one of the custom harnesses, it was something like $1,000.
 
I looked at Autowire, and the price is good BUT . . . all of the reviews said you had to move to a 1 wire "GM" alternator and you have to change some of the switches inside to "GM style". And there was some talk of a $120 crimping tool that you don't REALLY need . . . but you REALLY need.

I'm probably going to go with the Painless one . . . and see what happens.

:)
 
I looked at Autowire, and the price is good BUT . . . all of the reviews said you had to move to a 1 wire "GM" alternator and you have to change some of the switches inside to "GM style". And there was some talk of a $120 crimping tool that you don't REALLY need . . . but you REALLY need.

I'm probably going to go with the Painless one . . . and see what happens.

:)

D i usually recommend going with painless because i think overall they are the best way to go. i threw the others out there though as alternatives because some people, for what ever reason, dont like painless.
 
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I agree with rbohm ,painless is a lot easier to install than most for some reason .I am about to do my fourth one and it gets easier each time .Like i said though get the 12 circuit harness because the bigger harness has so many extra wires it makes it a real pain in the butt. The harness i am about to put in my 35 Ford truck was the bigger 20 circuit harness ,spent the best part of the day removing the extra wires i will not be using . The only good thing is if i decide i want to add something in i will have a open circuit . Also unless you have the Ididit or Flaming river column set up for a GM plug in ,go with the street rod harness ,although you can cut the plug out . The wires are clearly marked about every inch ,but i need reading glasses to read them:crazy:
 
I'm going to need the 22 circuit because, short of A/C, I've got everything you can imagine. :D

I'm going to order it from Dallas Mustang probably tonight. I'll send you guys pictures!
 
You could always relabel a circuit if you need to ,i think you will find they have everything covered though .Mine had traction control and a bunch of unusable circuits .Just remove the wires you do not need .Slip a test light in beside the wire not needed and bend the tab on the terminal and pull the unused wire out after you figure out what you really need .I had a box full of wires left over .
 
Well, here we go. I'll try and post progress pictures as we go. Wish me luck!


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you probably already know these, but;

1: separate wires going to the various areas of the car. all the wires going to the rear for instance. make them a temporary bundle, same with the front, etc.

2: decide exactly where you want you want the fuse block before you do anything else.

3: the toughest part is going to be the constant termination of the wires.

4: make sure you leave a little extra wire at the end of the harnesses.
 
Yes ,make sure you leave a little extra wire ,it is easier to tuck a wire out of the way than it is to have a wire to short . Do one circuit at a time or it gets a bit confusing .Like rbohm said,mount the fuse panel first ,break it down as a front and a rear wiring and go from there . I use a pack of those small zip ties to single out the wires for a circuit and just cut them off after and before i tape it up .
 
I'm going out to get first round of supplies today. I'm SERIOUSLY thinking about painting all the stuff behind the dash and instruments while I have the chance. One of the worst things about doing your own car is that, lol, you KNOW what's behind all the pretty stuff.
 
I used painless on mine and loved it. Each wire is stamped with a number and also says on the wire where it is coming from and where it is going to. You almost don't need the instructions. If I remember correctly most of the connectors needed were there except the wiring connection for the column wiring (blinker and horn). They did however miswire a couple connections like dimmer switch and one other thing I cant recall right off so it would be a good idea to verify. It also had extra circuits for add ons such as electric radiator fan etc.
 
Okay, I've been slowly working on it due to the heat, but I've learned a few VERY SIMPLE things to make wiring your car a lot easier. I'm not done, yet, but I'm going to relate what I've learned so far both from personal experience and through the videos. Here we go.

First thing is make sure you have everything you're supposed to have from Painless. I got everything just fine, but it's important to look. Good job Painless.

Next, make sure you have a GOOD crimp tool that can do "factory crimps". these are little crimps done on the all metal terminals that fold over the tabs right. This is VERY important because you have to use this type of terminal when you reuse the factory connectors.

The videos online are VERY helpful AS LONG AS you do this one, simple thing, okay? And please don't underestimate the importance of this. On a '65 Mustang, most come with little bumper guards in the front and back of the cars under the bumpers. They're the little chrome pieces on opposite sides of the bumper. First remove the front ones. Then remove the back ones. Label the screws and all so you can reinstall them easier. Next, follow the same procedure for :leghump:ING EVERY OTHER THING ON THE CAR THAT ISN'T WELDED DOWN because most all of the videos and help movies are done on a "project car" which is code for "this car that has been meticulously disassembled by some former members of the Andretti family and two guys from NASA . . . then cleaned and washed in an IBM clean room . . . and everything replaced by brand new items".

Once you have everything removed, labeled, and properly organized, call the guys from Mustangs Unlimited, California Mustang, and anyone else you like, fly them to your car, show them the pile of removed parts, and have them quote complete replacement parts. Buy those because, basically, every bit of "help" you find online is for a BLOODY :leghump:ING NEW 1965 Mustang because, HEY, as well all know, do-it-yourself guys only work on COMPLETELY REPLACEMENT CARS and not some car they drive. Right guys?

Get yourself a 12 year old boy so you have someone who can properly read the wires. This is somewhat important. Evidently the little wire labels we use at work would make this product completely unaffordable.

Something else you need to learn is more code from the help movies. This phrase "verify the proper wires are connected to the proper terminals in the proper method with the proper tools" actually translates into a 4 hour internet investigation into the usage and the application of the word "proper".

To their credit, Painless uses the REALLY NICE plastic coated terminal on most of the wires. These are great! What would make them greater? Being able to reuse them after you have to cut 90% of them off because, HEY, THEY'RE NOT USED!! You see, you have to cut them off to crimp on the "factory type terminals" which, ironically, use a really special crimp tool that no one EVER NEEDS . . . except for factory crimps . . . THAT NO ONE USES THAT MUCH NORMALLY. They're happy to sell you the tool for about $100, though. To be fair, it's not their fault. That's what Ford uses.

Okay okay, so it's not that bad, and I'm having a frustrating day. On a more serious note, it WOULD probably help if they gave you some routing ideas. That IS "painfully" missing. To me that would have been an easy touch.

Again, on a serious note, one thing you SHOULD get yourself ready for is the discovery of every nasty, dirty, and rusty part of your car. Basically you see all the dirt you never normally see, and you see all the little components that look like crap and probably function just fine . . . but it's depressing sort of, especially after you spend a fortune on nice paint, wheels, and tires. It's like you'll want to spend a few grand on a bunch of parts that typically get zero attention otherwise.

Off to hit it again. It's really not THAT bad, and the kit is pretty nice. I'll probably get it done okay, but it's been frustrating today.
 
D, one of the reasons that painless doesnt provide routing suggestions is because most people are doing a custom wiring install, not a factory one. also they figure that you removed your old harness and will probably run the new wires where the old ones went.
 
One other suggestion, In my case I have a 66 fastback and with my painless harness kit they sent me two different diagram booklets. I think one is for 65-66 and they other for 67-68. They look identical (if like me you didn't pay attention) but have different codes/colors. When I first wired it I used the right one but later on when I blew a fuse and tried to run down the issue I accidently grabbed the wrong book and was thoroughly confused for a good hour til I looked on the front cover and saw I had the wrong diagrams. I was minutes away from ripping things apart and rewiring. Do yourself a favor and immediately toss that book that doesn't apply.