I have a 65 Coupe that I've had for 10 years and the wiring is bad news. When I got it the previous owners had cobbed 1/2 the wiring and it is impossable to trace wires because there are butt splices everywhere and 3/4 of the wire colors have been changed. I have a color coded wiring diagram which is useless because of all the changes and I have to admit I've been forced over the last 10 years to make several changes myself.
I started it up this past weekend for the first time since November and it runs great but after 5 minutes I had no radio, lights, blinkers, fan etc.. so I need to trace things out this weekend and see if a mouse got to things over the winter or I blew a major fuse???

I would love to just purchase all new wiring harnesses but 50% of the wires would not be useful because of the changes that have been made over the years.
Things that are different include: New 383 engine with MSD box and electronic distributor, radio now in glove box, previous owner removed door switches and filled in holes, I have 6 tail lights, electric "Be Cool" fan, and the list goes on....
I was wondering what others have used for wiring harnesses if they were building restomods. I've looked into Painless harnesses but they don't have circuits for the headlight buckets and a few other items.
I do have a lot of control wiring experience but not in cars and they are definately two different animals. I was tempted to just purchase a new fuse box and start from scratch.
Any suggestions would be appreciated from someone who has similiar problems.

Thanks, Mark

 

If the main harness is chopped up get a new one, then just add wire for the aftermarket radio. The engine harness,make your own.I've never understood why someone would cut up a harness, it never ends well. I'd also replace the rear harness too, see if you can get the supplier to add the 3rd tail light to it. Good luck

 

All the wire harnesses are made by 2 companies. Lectric Limited ttp://www.lectriclimited.com/ and M&H http://www.wiringharness.com/ in California. Both very good companies.

Don't be cheap here, as nothing is more terrible than a vintage Corvette burning to the ground because of a electric fire.

They make the main assembly with fuse block, that includes the head lights, park lights, accessories like air conditiong etc. The starter / Ignition harness, and tail light harness are each seperate items.

And, if you have a special need, they can add it to your harness and make you a special modified unit.

 

Nothing will test your patience more that wiring. But the only solution is to work one problem at a time, methodically such as you would with your controls experience. They are after all very simple 12 v systems. I have gotten alot of help from the guys at
Madelectrical.com, there little book was actually helpfull. By thinking the way they do it takes the heavy current items off to a new clean circuit operated with relays and lets your original wiring operate only very small loads. It really worked for me, mine was pretty hacked up and Bubba-fied. Fix the obviously really bad things (I found circuits taped, with three different guages and colors). Remember in the past these were just old used cars and definately get the attention they do now.

 

A new engine harness is $157.00. I really don't see the point of trying to cob a harness up unless you really want the challenge of making your own.

 

My main dash harness was also a burned up disaster when I got the car 24 years ago. I have overhauled it twice, once after I got the car, to replace burned wires with correctly coded but larger gauge wires, and a second time to add factory style 12volt connectors for accessories. The connectors come from junk yard GM harnesses and are strung from new spade lugs in the original factory connectors at the key switch, light switch, etcetera. When replacing a wire, just add another short wire of the same correct color to the spade lug and insert it into the factory connector in place of the wire and spade lug that you removed. That way, all you need to do to have a factory appearing harness (for correct restoration purposes in the future) is clip off the added wire where they emerge from the spade lugs.

The male and female spade lugs are still available from vendors, as are the correct color wires in replacement and larger sizes, and the nonsticky harness wrap (although unwrapping a junkyard harness will provide wire and wrap). It will not cost as much to create a custom as a new harness would, but it will take a few days if you intend to solder the crimped lugs to the wires (like I did) and then coat the contact surfaces with conducting lubricant to forestall corrosion.

 

AUTO5

I'm not talking just the engine harness I want to change everything where practical over to new.

It's not a money issue, I just want it correct and easy to trouble shoot in the future. Right now if something blows I don't know what fuse it's connected to or where the wire originates. I want to limit the possability of a major problem and have peace of mind that I can get back home after a trip.

You guys who build Grand Sports, do you use custom harnesses?

 

Then change the harnesses as soon as possible.

 

I wasn't discussing the engine harness at all. I use a stock engine harness.

My main dash harness supplies power and outlets for intermittent wipers, cruise control, CAS stereo, reverb stereo booster, alarm systems, electic fuel pump, and ipod charging.

The relays, breakers and fuses to control the rad fan, auxiliary headlamps, and to supply 50amps to the cabin are all added engine bay wiring with no physical connection to the engine harness.

Here is how most of it connects: http://home.mchsi.com/~magicv8/index...g63-67mods.jpg

 

Markymyster, sorry I didn't mean to imply anything regarding price of a new harness just that for the price point, it's doesn't seem really worth trying to reinvent the wheel unless or course you enjoy the challenge. However, with the stated mods, it sounds to me like you could still use all the stock harnesses. If the dash mods consist of an aftermarket radio in the glovie and abandoned courtesy lights, what would be better than using a reproduction dash harness as well and tape up the few circuits you don't need? If you have a large load like magicv8, his setup is perferct in addition.

 

Either make your own, or buy new. Whats cheaper in the long run, wires or vette burning up. It could burn up during the nite in the garage.

 

American Autowire makes modded harnesses
http://www.americanautowire.com/

 

Thanks Dave "MagicV8"
That's a very impressive diagram with all your extra options.
Looks like you have all the comforts of home in your car.

For some who might have misunderstood my origianal post, I am not trying to take short cuts or save money I was just looking for suggested options on which direction different members have taken when they had a car that was not exactly bone stock. The most important thing to me is reliability and safety not $$

Thanks everyone for all your input. I will look into each of the companies you suggested and see who's harness' would best suit my needs.

Mark

 

The alternator fuses, the fusible links and the 50amp manual breaker on the cabin supply are all for reliability - from lessons learned during the 24 years I have owned my Sting Ray. Also needed for the factory battery meter is a 1 or 2 amp fuse on one of the meter terminals, and if you want it all: add a fuse on the lighter, on the pink ignition wire, and on the brown accessory supply line - none of which are on my car (I'll get to them someday).

All the added accessories on my car have inline fuses. The reason that the 135 amp alternator has 2 fuses, is to individually protect the factory harness (60amp) and the added rad fan and driving lights (60amp).

 

One of the very first things I did to my '65 was to replace the full harness / everything with a kit from Lectric limited.

I too have many of the additional things you mentioned (electric fan, stereo upgrades) and more (H4 headlights wired direct through relays, multi-point security system, additional fuses, amps and 12V power to the rear.) All that extra stuff can all be patched into the new harness and you'll be glad to have a confident base to work from.

I can't speak for other suppliers but from my experience it was a real pleasure to work with what LL supplied. The harnesses, crimps, connectors, wire lengths, gauge and colors were all correct and of very high quality. Didn't find a scuffed wire or weak crimp anywhere.

 

Five (5) words ===> New Complete Lectric Limited Wiring

Then you have a GOOD - SAFE base and work from there

George

 

I love wiring. I would buy a completely new harness, even if it's from painful. If you get the 18 circuit one you can use another circuit (that's included, but you are not using) to run the headlight buckets.

You didn't mention if you had power windows, You can use that circuit for other things.