So I'm going to replace my 66's main engine harness and decided this would be a good time to upgrade the electrical side of the house while I'm at it. What I would like to know is if my ideas are sound or if I should go about things a different way, and also what other ideas I haven't thought of. This will all be run off a stock 61 amp alternator.

First things I'm considering is the addition of fusible links and/or circuit breaker on the engine harness (I think 67's had 6 fusible links) to protect the harness. I was going to add a 40 amp circuit breaker on the solenoid lug to feed the 10awg main power lead. I woud also like to add something to the 12awg power feed going to the dash, but was not sure what size circuit breaker to use (30amp?) or if I should just use a fusible link?

I have already added a 2amp fuse inline with the ammeter, do I need anything else fused under the dash (clock, lighter, etc)? If so, what size fuses.

I am also running relays to the headlights. What I would like to know is what gauge of wire did people upgrade to when they did this conversion; 14awg, mix of 14/12awg, or all 12awg? I plan on tapping into power off the horn relay. From what I can tell, the 1966 horn relay only has a 14awg wire powering it from the splice in the engine harness. Is it best to upgrade this wire to 10awg and rewrap the harness?

I also plan to switch to a solid state voltage regulator.

Anything else I should consider?

 

Anyone?

 

Are you a electrical engineer? Neither am I. The stock harnes design worked great for the last 40 years No reason why it can't work now

 

I decided to go with an aftermarket "hotrod" harness for my 65. I bought one off eBay, new, for under $350. It's an American Autowire harness. It uses more modern fuses, relays and fuse panel. I previously installed a 100 amp alternator. The harness is in the garage waiting for time to install it. FYI my car is is where near original or stock.

This the one I bought.

http://www.americanautowire.com/highway22.html

Tom

 

Well I'm not a EE, but I am an engineer, so I guess I can't leave well enough alone. And in 67 GM made a few little improvements to the wiring harness, with that I figured I could make the same, if not a few more, improvements while switching out the engine harness.

 

When I did headlamp relays (on another car, not the Vette) I ran 10 gauge wire from the battery to the power strip for the relays, and used the stock gauge wire from the relays to the headlights. Since the wattage of the headlights is stock (55w/60w), I figured the stock wiring would be more than adequate.

 

MADELECTRICAL is a good resource for upgrades if you haven't visited it yet:

http://www.madelectrical.com/electrical-tech.shtml

 

Where do I start. I upgraded the alternator to a later corvette year with the single wire and I think that was a MAD kit upgrade. I found the stock alternators couldn't keep up with the MSD and the H4 lighting especially when activating the 150 watt racing bulbs (Cibie units straight from LeMans). I found the battery discharging due to the load before I upgraded. I also wanted an alternator that I could buy from a parts store is why I picked a mid 70's year wired as the MAD kit Schematic. I chose not to run fusible links anywhere because of the pain in the rear of troubleshooting one. To do a continuity check for an open circuit, you have to disconnect wiring on both sides (not fun and time consuming especially if you forget where the fusible links were installed. I put some military barrel connectors into my wiring, finding insertion pins for heavier gauge wiring! For a stock connector, you can get a pin release tool, flare new pins lightly, solder a slightly heavier gauge wiring maybe loosing a few wire stands (thus soldering gives gauge mass back that was lost with snipping a few strands), but stripping insulation right to the pin top, and I shrink wrap (extra protection from shorts and heat) shrink my electrical with a heat gun (no crimped wire connectors especially with the dangerously cheap plastic (red, blue, yellow sleeves). When Splicing I use a fold technique, twist and solder with shrink to splice if not run to a wiring block or component. For the pins in connectors I do crimp and solder. I run all pro level rings and spades with a protection spray. Relays and isolation is a choice. I fuse everything based on calculated amps and wire gauge/circuit loading. Etc..

 

I completely separated out my ignition to coil starter (battery) circuit from all other circuits. That is on its own fuse and changed the ground to a split engine/chassis (two grounding points) just for that circuit. In other words, regardless of what shorts out or happens and whether I have lights working or not, Clock working or not, turn signals etc. I can still start the car and drive it on the simple circuit and naturally with an overall upgrade of wiring gauge etc.. It is all wired direct. Thus I can pull all fuses except the ignition and start the car. Then for troubleshooting I can put one fuse in at a time to test circuits for troubleshooting on a short. In other words, if some problem is knocking down my 12V, then I pull fuses until the 12V is not shorted with hopes that the short isn't in my basic wired ignition. I hope I am making sense. I did this back when I was working on Military weapons and computer systems when employed by RCA/GE Government systems Services and DynCorp Engineering. I am rusty on all of this and would have to pull out my home made schematics on my Corvette electrical to refresh!

 

Don't use flux core solders. Use the solids and a brush on flux and wick it thru with the iron to melt thru to the heat. Burn off as much flux in the process of application of the heat and then clean flux with alcohol.

 

Yes, I am an electrical engineer. The stock harness design worked adequately, but some of the suggestions the OP wants to use are very good safety improvements and will provide some benefits, like the electronic voltage regulator. It's not a matter of the stock stuff not working, its that technology has improved, shall we say, just a little in 45 years. There are some things that do provide extra safety and better performance.

And some of you are downright road hazards with factory stuff - anyone driving his car on unlit roads at night with factory T3 headlight bulbs is taking a needless risk. Specially of the C2 crowd that sre getting old and can't see well at night as it is. Yeah, keep those factory taillight bulbs, too, and let some moron rear end you because he couldn't see you.

Too many descendants of Ned Ludd on here sometimes.

 

Too many descendants of Ned Ludd on here sometimes.[/QUOTE]


OK. I had to look that one up.


Supposedly, Ned Ludd was a weaver from Anstey, near Leicester. He is described as an "idiot" or "half-witted", suggesting he had a mental disability.[1] In 1779, either after being whipped for idleness,[4] or after being taunted by local youths,[5] he smashed two knitting frames in what was described as a "fit of passion".[6][7] This story is traceable to an article in The Nottingham Review on 20 December 1811[citation needed], but there is no independent evidence of its truth. John Blackner's book History of Nottingham, also published in 1811, provides a variant tale, of a lad called "Ludnam" who was told by his father, a framework-knitter, to "square his needles". Ludnam took a hammer and "beat them into a heap".[8] News of the incident spread, and whenever frames were sabotaged, people would jokingly say "Ned Ludd did it".[6][7] Nothing more is known about the life of Ludd.

Thanks and you are awesome,

Dennis

 

Thanks for the advice and tips.

 

Which led to the term "Luddite" being tagged on folks who stick to the proven old ways and refuse to accept new technology.

 

I can only hope to meet you someday. You are also awesome.

Dennis

 

What I wrote is in consideration of the fire hazard. Bare minimum, most C2 owners should change out the main harness. The lump solder grounds are at the end of there life span etc. Improving for safety and performance is a good thing! I agree!

PS the Mad kit that I used about 22 years ago (about 1990) was designed to change over to an integral voltage regulator alternator.

I also run the much brighter LED bulbs that are designed for the stock bulb socket. The road hazard post is valid.

 

What I wrote is in consideration of the fire hazard. Bare minimum, most C2 owners should change out the main harness. The lump solder grounds are at the end of there life span etc. Improving for safety and performance is a good thing! I agree!