Pros And Cons Of Universal Wiring Harnesses vs Original Or Reproductions- Which Is Best For Your Car 

I rewired my 58 chevy with a universal harness. It worked great. I also bought the proper crimping tool. i spent around 300$ on a 14 circuit kit in 2018 since the 58 has so few electric components. Taking ones time and thinking about things BEFORE actually doing them helps a lot with wiring.

As the old saying goes, "Slow is Fast", when it comes to doing electrical work. Take your time and treat it like a project manager would with any large project that has multiple complex systems. Segregate the subsystems and create task lists to address each system one by one. Usually when you start writing things out you see how certain tasks can supersede other tasks in their priority. It's also one of those thing were you need to keep tabs on your mental self while you are working on it. If you start to get tired, hungry, or sore, then that's generally when the mistakes start to happen out of frustration and it's time to take a break. Then, that's where the biggest time and money sink can come in when you have to start redoing things to fix your mistakes.

I like re-pro with additions. They can run extras like fuel pump, fan and water pump, but still connect with original connecters. When I buy an old car, the first thing I do is to pull out the spaghetti and start from scratch. Remember, wires corrode from the inside out, that's why battery cables must be replaced periodically. BTW, I use Painless when I must replace wiring.

I agree. Original layout and hardware is the best for stock builds or anything analog like that. I especially stick with stock wiring harnesses if possible with 80s digital cars and up for the sake of being able to consult a service manual for easy diagnostics.

I used a Painless brand harness for a '54 Chevy truck (5700 Cab Over Engine w/5.9 Cummins diesel registered commercially...at the time) and had good results BUT...! My near disaster happened thus: I hit the road on an important mission. The alternator started overcharging. I ran 100 miles, and got worried about frying the batteries. I pulled over and WITHOUT SHUTTING THE MOTOR OFF... Pulled the big hot cable off the alternator. I took off, got about 3 miles down the road before the cab filled with burning plastic smoke! Found a pull out, grabbed the extinguisher!!!! K, it was the resistor wire, sending 12v to the alternator to tell it to charge, with the main cable disconnected while running, tried to send the juice down the frail resistant aluminum wire in the harness!! FIRE! So pulled it all down, made a mess, made the delivery, reinstalled a diode in line. Lesson: shut the fucker down to kill the charge signal!

I love how the owner kept the dash original! Nothing aftermarket can match the beauty of those muscle car dashes from that era.

Iconic Chevy 2 intake manifold.

Uncle Tony and Kiwi are the dynamic duo.

UT - that "white powder" you mention where the copper wire had turned to a white powder inside of the jacket - that is a symptom of Copper-Clad Aluminum Wire failure. It is not actual copper wire. I've done a lot of aftermarket audio / alarm / remote starter work over the last 20+ years as a hobbyist, and once in a rare while I'd come across an inexpensive set of speakers or starter that had a bundle of "free" wire included with it. Often times, that wire was CCA ( Copper-Clad Aluminum ). In a home audio environment, CCA isn't that bad - typically, you'll use one size larger, and it'll do just fine for your home theatre or whatever it may be - and it is DIRT CHEAP - pennies per foot. In an automotive environment, and especially with poor quality wire insulation and/or wire that is not extruded, there will be air pockets inside the wire jacket. Those air pockets can form condensation - condensation is water - water causes oxidation. Any kink in that CCA wire and it's going to expose the aluminum under the very thin copper coating on each strand - and it'll oxidize faster than you can say "Made in China". Avoid CCA at all costs.

The gremlin in wiring is chaffing. Just thinking about the wiring chaffs my rear posterior. You forgot to mention two important things you need. Excedrin for the headache and dones back pills for the injured back when wiring. Back in day I knew a guy and he commanded so much respect throughout the entire local car community. Small wiry guy. That was a wiring magician. Well we all got older and he retired. He was fair and his prices but he done well. Well I've watched kiwis explanation on his channel and I'm still not all wired up to do wiring. You guys are great together! And individually as well. Thank you so very much for introducing kiwi on your channel.

I build hot rods for a living. I've wired a whole bunch of cars from scratch and there's two manufactures I'd trust. American auto wire is good if you don't like wiring cars and want to plug in connectors and don't plan on changing things too much. (I don't like how they label circuits so if you need to make things look show ready or have a lot of accessories it gets annoying) If you are a little more savvy and trust yourself to not make a mess Ron Francis kits are awesome. High quality and good instructions. I'd skip painless wiring or anything off ebay/amazon.

I got the Speedway Motors 22 circuit for $200 about 4-5 years ago. Everything is still working fine.

As you have said with cams and so forth, check everything. When I am working with wiring I check each strand with an ohm meter for good conductivity. Not as bad as it sounds as I can only work with one wire at a time anyway!

Kiwi's. Channel rocks ! Awesome workmanship.

In Kiwi's situation with this particular car, I'd spend the time to pull out everything they've already done, and start again from scratch. As Kiwi said, he owns the whole wiring, so best to do the whole wiring. If anything the owner has already done fails, they'll put it back on Kiwi. Personally, working mostly on stock, standard cars, I take the existing loom, where possible, keeping as many original unobtanium plug insulators that can be safely salvaged, and replace all the physical wire and crimp terminals. Essentially making a factory repro. Learn how to crimp correctly, it may seem like a simple, anyone's grandma can do kind of thing, but it is an art, and requires a quality crimping tool. Thanks for another great video Tony, and Kiwi.

I was talked into stock harness and after listening to this I’m thankful I did.

Thanx guys, appreciate the content.

I rewired a restomod military truck with a kit from Rebel Wire from right here in good ol' Tennessee. I called them to make a few changes and still got delivery within a week. If you have questions, when you call you'll talk to the guy who built your kit. Great quality.

I wired my first scratch built 53 f100 at age 15, all color coded and fused, I guess 43 years later as a journeyman mechanic, electrical trouble shooting is still my specialty.

Hey Tony, Tim here, i just finished re-wiring my '64 Tempest......old wiring was giving me fits (brittle, hard, corroded, etc) under the dash......the firewall fwd was good, cuz i bought original stuff when i built the car.....under the dash had become AWFUL!!!.....new, correct 1964 harness from my guys at Ames, was $600 ......NO!!....i bought EZ-wire 12 circuit (bare bones) harness for less than $200......yes, it has no connectors for lite sw, ign sw, directional sw, etc, but mine was to far gone......i used new spade connectors to wire in the lites and ign....so i only have the one terminal per wire, but alot of DIY guys dont know what to do.......my car functions well now, i had to butt connect the turn signal sw, and the rear ribbon cable......but all else is new.....reasonable quality, but you GOTTA have experience!!!!!.....Harry Homeowner will most likely mangle it......just a quick story of my dealings with wiring, as it was just completed a month ago......the EZ-wire harness is reasonable.......LOVED the vid!!!....PEACE to you and Kiwi (who i sub to now as well).....THANKS GUYS!!

Those painless kits a godsend. They work mint

im slowly going through the wiring in my 77 J10 Honcho, there is no reproduction harness available and i wanted you to be able to pull up a factory diagram and find what you needed. i sat down one day and wrote down every color and size of wire o would need as well as connectors and terminals. i completely rewired from the bulkhead connector to the engine and the front lights. everything going to the rear of the truck will be next, surprisingly under the dash isnt all hacked up and is in really good shape. i always dreaded wiring until i started watching eric on the south main auto channel, he just has a way of dumbing things down.

What a rat's nest! Hard to believe that customer messed so bad. So funny that Uncle Tony can never remember Kiwi's Chocolates & Corvairs.

Awe yes Kiwi had the perfect word to describe wiring issues, TORMENTING ! I had had hair when I started this project!

I agree with kiwi 100% you definitely get what you pay for when it comes to wiring harnesses or any aftermarket performance part really but like he said most people don't want to see wiring and they don't want to spend $1,200 on a harness so they go and buy the cheapo $300 harness thinking it's going to be the same but it definitely isn't, the cheaper it is the more you're going to have to modify it to get it to work and fit properly the high dollar harnesses are usually plug and play everything is cut to exact length with the proper connectors and ends. I've been thinking about mounting a fire extinguisher in my car for a while now along with master battery kill switch and after watching this video I'm definitely going to be ordering some more parts tonight!

M&H wiring harnesses, put one in my 65 Chevelle perfect fit.

I put in a repro harness in my'58 Pontiac and it fit and worked perfectly. For my '36 Chevy coupe, I've ordered a EZ Wiring 21 circuit kit. It's not one of the real expensive kits but not the cheapest. I'm hoping it'll be good. I'm installing it because, when I looked under the dash to install EPAS, I found there is 4 inline fuses and that's it! No fuse box. And this was totally rewired!

thank you

Wire nuts in auto electrical systems drive me crazy. I’m a diesel truck mechanic so I do a lot of electrical repair and have seen wire nuts everywhere. I’ve seen 110 wall switches used, drop cords used as harnesses, speaker wire powering lights. The worst is when you get a ‘custom’ truck with 100 add on lights and they are all daisy chained together with scotch locks. I removed a 5 gallon bucket full of extra/old/un needed wiring from a truck where numerous drivers had added their own lights and radios and ran jumper wires instead of actually fixing the problems. Lucky me, I’m the “electrician” at work.

I grew up around Italian families and had been to plenty of sunday dinners, I know my way around spaghetti!........Take my advice, a good sauce is EVERYTHING!....in THIS case, wiring should be left to those with adequate experience as a car fire in your garage 6 months after its finished can take out the car and your house DO NOT SKIMP ON QUALITY!!

Good video UT! I went with an economy universal harness for my 66 Rambler ($75.00?). While I had to tie it into my stock switches, the original harness was a nightmare and had the 5 fuse Masonite panel. Where I could I replaced the stock switches with GM switches for ease of installation. If you have basic needs for your car they work good.

Good job! I pulled the wiring harness out of my 73 D200. That thing was rotten, so I am building a harness to run the engine for starters.

I just finished re wiring a 1986 f350 for a customer. Wish we would have went with a universal harness to start with. Ended up building it all from scratch interior, under hood, and all the wires under the truck and it took way longer than it should have but it fixed the corroded and hacked up harness for good. No more weird electrical issues

you can re pin the old plug with new pins on new harness with the right tools or TAKE YOUR TIME and use a small set of flat blade screw drivers to get the old pins out on say spade connectors other stuff it gets specialized. but factory harnesses are the way to go for most of us. if you need a extra circuit just put a small sub panel in. good advice.

...Uncle Tony is the ultimate car guy...

Kiwi is 👌- UTG turned me on to him

Great mnemonic to consistently mis-name Kiwi’s channel. Seriously. It gets folks to remember it.

I quit using crimp fittings 20 ish years age and got out my soldering iron, never looked back!

I put a reproduction harness in my 68 Olds 442 and it went in like a dream, no issues and it works perfectly. I wouldn't even consider an aftermarket fits-all harness.

I fully agree. Always use oem harnesses where possible

someone rewired my 66 bisquick ,With freakin blue wire ,every damn wire under dash Blue but never had a issue luckily

I couldn't agree more. I need to rewire my 65 El Camino soon and will use a factory style replacement. I have played with the customs and they can be a real Pain. I have also been involved in total custom race builds and then it's start from scratch and build it yourself deal.

Proper size fuses and relays are your best friend. I added LED with resistor to control brightness. These can make some power points easy to test with out a electric meter/tester. Adding hidden a kill switch some were is a good idea. Make your own diagrams as you go.

Bad ass Chevelle right there .

Depends on what restoration results you want. Good idea with more options for mods on most restomods and hot rods. I say go for it.

ah sweet finally a real gem on this channel, 67 Chevelle, should have uploaded the video for tomorrow for Hump Wednesday (hood)

Good stuff 👍 your probably going to upgrade the alternator lights etc and add relays so pull the wiring out of the engine bay and replace the lot, modern marine type fuse box with additional circuits helps too, battery in trunk and a master switch, buy your own wire & connectors and do a diagram.

I bought the speedway universal 12 circuit for my wife's 66 mustang. I believe if you take your time and do it right you have less issues.

I worked on a fleet of old Grummans and Olsen curb masters I bought several of connectors and different colors of wire and made my own harnesses they were severely hacked when I got to them I also had several different wire plugs for various switches I bought to fit the connectors

I wired a efi 5.0 mustang using the 35 year old efi harness which I converted to standalone. That harness was out of a junkyard car with a quarter million miles. Worked just fine despite all the busted connectors, mile deep grot and stuff. They made these out of goid stuff back then......it does have Term X on it now though.

Love u brother man. There’s always the option to ignore snd bandaid 😂

Tony is lucky he can remember Kiwi....

6:55 that's a legitimate technique,Ford calls it a wiggle test. You'll be amazed how much stuff it helps you find that's wrong.

Thanks tony very interesting, what’s your take on PCV vs twin breathers? We have no emissions controls on that here just want the best preformance.

I did a 82 Ford bronco with a painless kit. Was not very hard at all. Used the factory wiring diagram as a reference.

Also depends whether the wiring is for digital or anolog, most digital gages etc use less power, they make them to light gauge wire, my two cents, all the best to yous and your loved ones

I'd be interested in how you guys with skills approach tucking all the wiring under the hood. Probably one of the most common hot rod modifications.

I used a Painless brand harness for ironically my 67' Chevelle. I couldn't have been happier. They are made in the USA. This was 15 years ago.

I love wiring videos. Specially the color coding. Being color blind is an absolute curse as far as wiring. Learned this the hard way in community college taking refrigeration air conditioning course. Have you ever seen a screw handle melt off. Scary. Failed the electrical but know the mechanical inside out. Labelling wire is fine but I’m still spooked.

I had a red one like that

I had to fix the wiring in a 32 ford pickup, it had a kit, it had so much stuff the truck didn't need, i just pulled it all and made my own system, my own panel with fuses and relays, all new switches, mid 70's ford pickup steering column, maybe in the right situation i would install a kit.

Original is always best. But I couldn't find a harness for a 73 Charger I was working on, it had been lit on fire by her jealous BF. I sat there with reels of wire and are wired the whole thing. It took a week but I did it completely stock using the original plugs.

Use high quality cross-linked wire and quality OEM connectors. If going custom use Centech 24 circuit fuse panel.

I’ve found harnesses (uni/repo) are often under gauged. And push together connectors need to fit tight to transfer current.

Nice 66!

Someone tough that it was a good idea to, not only do a fuse delete but also a whole fuse box delete on my 1967 F250. Not a fuse or fusible link anywhere to be found in it. So thanks for the advice i'll need it.

UTG love your videos... Ive rewired 2 , 80's cars and now doing a 05 ram, by-passing the computers etc. I use Ez Wiring... simple and hadnt had a problem. That car youre in, is just a bad job... and kiwi has a point, depends on your kit... wiring is simple, if im saying it is, then it is.

Get a kwik wiring harness kit. It's easy to wire and plus u will learn more about electrical issues with cars once u learn how to wire one up

What are your thoughts on adding a shunt wire from Mopar alternator to starter relay.

Now Back when Building Custom Van Conversions ,You could Either Free Hand Wire the Add ons ,Or You Design A Custom Wiring Harness Universal Fit For Dodge Ford or Chevy.

LOL this mopar guy loves his wiring

When wiring tail lights on a vintage car the easy way is to go to Napa and get a trailer wiring kit all the brake lights tail lights and turning signals are color coordinated wires

I started with spools of wire and wired my 63 C30 from scratch. Not best for everyone but was easiest for me as the truck is radically different from stock - electric fuel pump, electric fans, battery inside cab, electronic ignition, internally regulated alt, aftermarket gauges, universal turn signal switch.

I repair farm tractors, usually no harness available, I just make my own harness.

HOWdy U-T-G, wire - Wire - WIREY Thanks COOP ...

Would love a muscle car with just one wire :P. Just driving around in daytime.

A point to mention is that the original factory wiring is not readily available. If you're lucky, could get NOS but it's rare. Original factory style layout harnesses made or sold by aftermarket companies are still not like the original quality. So we don't have much choice really.

To say my 73 ford capri wiring was a fire hazard is an understatement. It literally caused and engine bay fire the landed my car in the scrap yard where I bought it. Good luck finding an NOS wiring harness for the capri. I bought a painless 14 circuit kit and wired it to all the factor switches. The harness kit was great it took me 2 weeks in my spare time to trim it up and locate everything nicely. Take your time and have a plan though.

I rebuilt a 67 Ford fairlane 30 years ago and I just removed the original harnes and removed all the tape and removed any bad wires and replaced them and found two wires melted together in the harness in the channel under the door sill cover going to the taillights and cleaned the harness up and re wrapped it and all was fine

I work on emergency vehicles fire trucks and ambulances mostly. I could make a mini series of what not to do when wiring. When I have to make or put back a harness I always use the factory terminals that hook to the switches gauges etc. I hate butt connectors. They have there place doin’t get me wrong. But wire nuts need to stay in house wiring.

There is a place and time for the universal kits. Drag cars that get driven on the street now and then, or a total Resto mod. My car is 99 percent stock wiring application wise right now and I'm running a good original fuse block and headlight harness. The engine harness and taillight are new reproductions. I might add electric power steering, and an electric AC compressor someday, and if I do I'll just add a couple circuit fuse block in addition to the existing one. If you are paying a mechanic to install a universal harness... you will be under water if you chose that route because you thought, it would be cheaper. I did have a friend that had a minor issue with his new reproduction harness. A pin didn't get put in enough lock and backed out rather than making a connection. The plus side of the original harness design is there are wiring diagrams everywhere to quickly figure out what wire is what and where the problem is. If you are choosing to run a universal wiring harness, I would recommend a brand that provides a wiring diagram, or at least make one of how it gets wired. The only plus side in my opinion is that the universal kit probably uses a modern fuse that you can find anywhere. I had to struggle to find a couple of the original glass tube fuses in my area, so I know I need to stock a couple if I'm on a trip, that or wrap the blown fuse with tin foil... I've never done that before, but heard it was something done at one point in time. That tip could save the day or be the worst advice ever!

That's the most beautiful car ever built. I've had like 6 of them.try to beat a 67 396 chevelle.not many hi horse cars around but the 325 horse 🐴 cars rocked

Love mopars , only had five six engine harnesse fires over the years . Lol 😂!!! 🔥🔥🔥

If the wiring is brittle, can you heat up the harness and make it supple again?

I am very picky when it comes to fuses, wire size, color and solder all connections with shrink tubing. Using a digital multi meter, amp clamp for sizing fuses, redundant grounds and quality of wire plus the type of installation. I don't understand a guy or gal who do not understand amperage over distance, voltage drop and to hell with crimp connectors and Scotch Locks! I will remove the terminal from the connector, then replace it. I guess I am lucky I bought the Kent-Moore crimpers of three types. Core crimp, insulation crimp or weather-pak crimp, plus a set of remover tools and a jumper set. Today, many good amp clamps that have a digital readout. Learn how to use these tools, learn voltage drop and always use a good fuse layout because they protect the wire, not the component! It breaks my heart when I hear a building with 50 classic cars burn't to the ground. A part of me deep inside dies off. It is true that squirrels are responsible for 20% of fires as their teeth grow and they chew on wires, but it takes one 1967 Dodge Charger without proper "ANL" fuses to protect the battery out to the starter with a 150-200 amp (Circuit #1) and then the alternator and entire car,(Circuit #2). And as the video shows, cooling fan wires ran thru a metal hole in the fan shroud. Why? Classic Camaro, concourse restoration with metal, body work, $12k in paint, $350 Chinese wiring harness, self installed. You should be in government! Sorry, I am very picky on electrical, (4 kinds of insulation) really cheap, cheap, good and really good) DK, ASE Master Tech since 78.

Never had an issue with Painless wiring harness for a specific vehicle type.

I like wiring. Most of my friends think I’m nuts. I won’t deny it, it probably helps.

Had to do a major rewire in the engine bay of a Hilux I bought after the previous owners dog had jumped in there & chewed every wire it could see to pieces for some reason

Another factor in deteriorated original wiring is a leaky windshield, which allows water to drip into the fusebox, instrument panel and all those under-dash connectors.

I like the way germans do their schematics: top line is source, bottom is return - use as many pages as needed. Put devices between the two, and just add as needed. You do want to group interlocks and pilot/lockout relays next to each other on the drawing for quick/easy troubleshooting reference. Example? Maybe ignition kill relay on a low oil pressure switch [which requires a momentary switch to bypass the interlock for starting]. If wiring from scratch, just go down the line, one device at a time, adding fuses for sub groups as needed. Above all...use a bulkhead connector: if you ever need to pull the engine or pull the body off the frame, it saves enormous headaches. No individual wires passed through a grommet should be installed, except for relocating battery to the trunk - a cord grip works in those cases to provide a seal and prevent chafing.

The best kits have the wire labels every 6" or so.

I made a battery cable out of some leftover cheap aftermarket 2 or 4ga wire that came in a sound system amp wiring kit off Amazon and the wire turned to white powder too after a couple months. I have no idea why cheap wires do that but they do. I like to keep my wiring stock when I can

The stock Chrysler bulkhead quick connect that sends full alternator amperage through to the amp gauge is not a good design. They in fact knew this and had a straight through with a formed grommet for the police car package. The stock passenger car bulkhead connect was for quick assembly line use.

could you do a video of a tbi to carb conversion

It may take time but why not use good quality wire that maybe the same color of each wire minus the stripe just replace each wire and use existing wire for measurements / lengths to go off of ? mainly on older vehicles that have very basic wiring harnesses

Having 12 foot long Multi-meter/beeper leads is key to making wiring troubleshooting much easier.

Biggest problem nowadays is cca wire (copper clad aluminum) it's cheaper than 100% copper but will oxidize like he was talking about turning to a white powder.

Nice wheels.........

Hey Tony,old Ford probe

I’ve done a few cars. American auto wire kits are better than oem. Everything works perfectly. I loom every wire with a painless braided loom