80 vette with LS1/4L60

I have had wiring issues for the last five years. I have had it with the hacked wires and all the issues. I am contemplating removing the old wiring harness and make my own from scratch. Has anyone done this? A new harness for stock setup can be up to 2k but I need very few items from the stock harness.

My logic is I need windshield wipers, headlights, taillights, fuel pump and power to accessories. What else is there? When I upgraded the headlights I build my own harness for them and the LS1 has its own custom harness too. Only a few wires plug into the power system of the car.

If anyone has some input, wiring diagrams or something like that I would highly appreciate the help.

 

Painless wiring universal muscle car kit.
Ron Francis expensive but nice.

I used EZ wire 22 circuit, instructions are the best and you will need to run additional wires for to complete some circuits as they werent in the kit. I have a post on here somewhere about the install.

 

I do extensive wiring modifications from time to time. AND if you have the time to put into it...I would get a wiring diagram and map out your ideas.

And...for what it is worth so we do not hear you scream in the future. IF you replace the wiring form a company that is NOT using GM design and colored wires. I hope you take the time to make your own wiring schematics...so IF something goes wrong...you have a way to find the problem...because if the wiring is different...using a GM wiring diagram is going to be useless.

DUB

 

Agree with DUB on the color coding. My car had most of the wiring (and connectors) under dash for gauges wipers etc hacked out as PO was making a road race car.

I happened to have couple old harnesses and spent DAYS extending and fixing up everything from the fuse box. One was from a vette, one was from a 65 Impala. I added a plug so the center gauge console can be unplugged and the gauges can be bench tested.

AND keeping GM colors so the wiring schematic is same as original!!!

 

One from scratch- that will take some serious time-a lot of different colored spools of wires. Um- turnsignals...horn...brake lights..Gauges...ignition switch

Don't know your definition of simple...but even I wouldn't call it that!!!

A Painless Classic car customizable is about $600...might be a lot easier to buy an OEM dash harness for less and just redo under the hood as you have a LS.

I wouldn't throw the baby out w/ the bath water- unless you are doing a track car...

I kept the OEM harness- and basically used it to trigger relays and added my own "sub panel"

And like Dub said- MAKE a wire diagram- use same wire colors through out. Like I used purple - same color GM used off the ignition switch for the starter wire.

ECU fuse panel by Richard Hayes, on Flickr

DSCN5030 by Richard Hayes, on Flickr

DSCN5177 by Richard Hayes, on Flickr

 

Maybe I have an unfair advantage, BUT being an old ET with experiences working as a tech/assy. aide for an engineering/security firm.....wiring a car is something I do blindfolded, including FI and all the senders, my wiring for the basic car is purposely obscured in the color codes, to deter crooks.......Like I prone to say, there is NOTHING stock about my '72 vette, from wheels through roof....NOTHING!!!!!!

except the chrome bumpers and maybe the door handles....

BTW, I buy no wire new, it's all tear outs from decades of cars/hotrodding, GM wiring except for the annoying white molex plugs in later sharks, and the bulkhead main wiring harness connector, I wire direct around all that crap.....the only parts of my harness that are stock are the front and rear lights, even though the lights on either end are not stock.....

OP, sounds like it's not a problem for you, really....just get a few diagrams from Wilcox or whoever he recommends and you be on your way......My son did an LS into a '57 Chebby pickup, and is he can do that without NEAR my electronic background, and you did the same thing, essentially.....feel free to PM me if you want, but it's not the big deal......

 

I just did it about 2 years ago on my 65 Impala using an American Autowire universal kit. It's a great upgrade and you won't regret getting rid of the old troublesome wire.

The harnesses with a fuse block typically come with the wires kind of pre-bundled how they expect it to route. I completely undid all the bundling and separated all the wires so I could re-routed the wires to go the direction I wanted as they left the fuse block.

Mount the fuse block and then route all the wires. Work from the fuse block out. Tie wrap the wires where you want them to route right up to the connector/switch/terminal they terminate at. Cut them long to get rid of the gross excess but make sure there is enough in case adjustments to the harness routing are necessary. Once you get the harness routed, go back and start terminating everything. You'll find you start routing and then have to cut back and adjust.

Make sure the harness routing clears the dash/radio/gauge cluster etc before you start terminating.

The terminals are usually Packard type. You can buy them in different places but they are a little hard to find. The source I used is gone and I don't have another offhand. I bought different terminals and connectors for everything and it was probably $100 or so just for for those extras. There are good ratcheting crimpers on Ebay that work to install the terminals.

 

[QUOTE=lionelhutz;1591076856]

Make sure the harness routing clears the dash/radio/gauge cluster etc before you start terminating.

QUOTE]

One of the biggest problems for me!!

 

I can 'say' this...I worked on a resto-mod thatw as wired up by someone else with the American Autowire harness in it.....and even though it worked....the ONE THINE I could not stand is where the wires went through the firewall. They were not bulkheaded. SO..the wire bundle went through and ran to 'wherever'.....SO when I was mapping out the wiring for the owner.....the person who installed it did not give ANY extra wire so the fuse panel could be pulled back. The wiring harness was routed so tight that trying to get a little bit of wire length so I could map out the fuse panel and change things in it due to not being correctly wired up initially...it was a ROYAL PAIN. I do use American Autowire and like what they offer....but for me....the harnesses need to be modified to make ME happy when a wiring bundle has to go through a panel.

SO...unless a person KNOWS what they are doing and STOPS and thinks about FUTURE SERVICE work...I would advise replacing the wiring harness with the correct factory replacement. Because getting on the level of what 'Richard454' is doing takes a person who KNOWS what they are dong and is NOT in a hurry to get there. I am NOT 'saying' that people can not do wiring....but from my experiences in having to repair electrical repairs...they fall short of doing it RIGHT and do whatever just gets them by.

DUB

 

It's easy to fix DUB. Don't take the firewall wires out directly behind the fuse block. As another point. The AAW universal wiring harnesses are bundled with the engine compartment wires at good 4 or 5 inches down the bundle and not directly out the back of the fuse block.

 

Yeah...I know about that. But it is still dealing with engine compartment wires that have no bulkhead connection like GM did where it is service friendly. But even having the correct terminals and crimping tools. I myself would install a factory replacement wiring harness and move on. I am 'funny' that way when wires are going through the firewall and they are routed and installed in a way that can cause for future service work to be a pain in my backside....because usually...I am the guy who will have to work on it again.

If it is a custom install like what 'Richard454' has shown...then I am buying bulkhead connectors and special connectors/relays and all that so the wiring is taken to the next level and very service friendly.

DUB

 

Got a link to a good bulkhead connector? Anything I've seen was way overpriced for what it was.

Almost none of the universal wiring kits come with a bulkhead connector. AAW update kits and one of the Painless kits are about the only ones.

For me it was completely pointless to buy a factory replacement harness then cut it up to make it work. That just made no sense. A universal wiring harness with a bulkhead connector was abut 3X what a kit without cost making the decision to go without easy. Routing the wires properly and there is no need to disconnect at the firewall until it's time to replace the harness again.

 

Yes I have links to MIL-SEC style connectors...but you would pass out on the cost. I use these on very special projects where money is NOT an issue....and being custom is the name of the game.

http://www.btcelectronics.com/spec-a...c-44-l-en.html

The problem that I have with many of the aftermarket bulkhead connectors is that the gauge wire size is limiting me in doing what I want when I have massive power through the firewall. Or the number of terminals in them are too low and is not going to work.

I use or Chaney up the bulkhead connectors with more terminal slots using GM bulkhead connectors. Due to as I wrote before..I can crimp on the factory terminals and cage them...and move on from there.

DUB

 

SO- is the consensus- "simple wiring harness" is really not a correct term...

I know Peter (Lionelhutz) wouldn't think of using these really nifty connectors -as they came off a German engineered car.

But I have found them pretty useful- and basically cost nothing off parts cars.

 

For decades now, all my cars have had the wiring done MY way.....and there no main harness/running/operational wiring connectors, they are all hard soldered and connected 100%



Funny story from some...jeez....almost 40? years ago....'72 Lemans/Pontiac at DCA airport picking up the kid's mom/my ex's Mother for the introduction so the ex goes to greet her mom and I set on the street/drive around....radio on, and so they load up and I go to start the car....

short form, 10 pm, borrow a flashlight from a guard, pull out crap from the trunk....jumper the coil, and the headlights with a lighter weight to the coil, and a major jumper cable I still have....from the fuse block to the underhood enough to drive the ~20 miles home

for some odd reason the old lady was impressed, ME feeling like an idiot.....

never did find out WTF happened to that car.....sold it years later.....

 

I know the Mil spec connectors but as you posted they are generally limited by wire size. We use them at work sometimes. There are also cheaper solutions than the full metal housings that would work just as well. But, the install would end up with a connector with a few heavy pins for the main power feed and then another connector with a bunch of light pins for the other wiring.

I could have re-used the factory bulkhead connector but it uses the twin-lock connectors and I'd rather pass straight through then use them.

I'd also rather pass the main heavy gauge power feed straight through before spitting it to multiple connector pins. Doing that just adds a measure of bubba to the car.

Overall, I just don't consider having a bulkhead connector to be that important. Running straight through is also the simplest and most foolproof way to do it.

 

YES 'simplest and foolproof' for installation.....BUT as for a repair/diagnosis...until you have a problem and have to find the problem...like I wrote...what happened to me...it was a total pain in my backside.

Two different ways of thinking and depending on the person...and HOPEFULLY whoever install this style of wiring harness stops and thinks about repairs/diagnostics...SO...both are correct. I myself...as I stated before...want a bulkhead connector that I can access so I do not have to tear a car apart to repair a wiring fault or just being able to access it to run diagnostics. I always stop and take time to think when installing something....because working on these Corvettes when if ONLY the designer STOPPED and took a minute to think about repairing it AFTER it was built...instead of thinking ONLY (assumption) about the speed to assemble it...my life would be a bit easier on some service operations.

DUB

 

I finally had a break from work to read all these posts! Great information!

What I have decided to do is replace my old harness with a universal one that has all the items I need. I will have to extend a few wires and wire the connectors on some of them which is fine by me. Plus, I met a guy who rewired his c3 and we started talking about the wiring issues. After a while I ended up at a hot rod shop and had new harness for 280 bucks.

I found 4 places that may have been causing my direct short for the fuel pump and I really really really hope it's not the Dakota digital board.

Today I have removed the harness from the entire car except the ls1 harness. I found wires changing color up to 4 times! Bare wires and some other Bubba stuff.

Let the fun begin and I finally get to use my label maker