1954 Wiring Harness Replacement

[Kim F.]

I am planning on replacing the wiring harness in the 54 corvette this winter. The car was converted to 12 volts by the previous owner. I am not planning to go back to 6 volts. This car is a Pennant Blue driver not a show. Does anyone have a suggestion on a vendor for the wiring harness? I have not replaced one in any car so I do not know if the 12 volt wiring harnesses for the 54 that say restomod will work.

[Richard M.]

Re: 1954 Wiring Harness Replacement

Kim,

Lectric Limited and M & H are the ones I use for wiring. Most vendors sell their harnesses. I use Zip Products myself. They sell the M&H products. I have also used LL with success.

E.G. http://corvette-parts.zip-corvette.c...ness&year=1954


I would not recommend a "restomod" harness. It'd be a nightmare to connect.


Rich

[Michael S.]

Re: 1954 Wiring Harness Replacement

[Richard M.]

Re: 1954 Wiring Harness Replacement

I think he needs the 53-55 6-cylinder harness since his '54 still has the 6 cylinder. I think the 55 V8 harness is physically different so it may not reach some 6 cyl engine related connections properly.

I believe, electrically, the harnesses would be the same whether 6 or 12 volts. Plus running 12 volts will mean that components will be drawing 50% less current through the wiring.

I'm not really knowledgeable on the early cars but jumped in 'cuz nobody else did at the time. Maybe some of the early C1 folks can jump in.

Rich

[Jim L.]

Re: 1954 Wiring Harness Replacement

I think he needs the 53-55 6-cylinder harness since his '54 still has the 6 cylinder. I think the 55 V8 harness is physically different so it may not reach some 6 cyl engine related connections properly.

I believe, electrically, the harnesses would be the same whether 6 or 12 volts. Plus running 12 volts will mean that components will be drawing 50% less current through the wiring.

This and the advice to avoid restomod harnesses (like Painless, for example) is good advice.

The harness for the 6 banger will have larger wires due to the greater expected current draw of 6V devices, but that hurts nothing in a 12V application like this. Too, every connection for the 6 cyl engine and accessories will be in the right location, greatly simplifying the install.

Jim

[Dan D.]

Re: 1954 Wiring Harness Replacement

I converted my 54 to 12V in 1961. Assuming yours is still a 6 cyl., then just buy a new 54 harness. Either of the 2 sources mentioned in post #2 should work fine. Do not buy a resto-mod. If your car has a V8, then a 55 harness is what you need. Keep in mind both 6 and 8 cylinder engines were used in 1955.

As mentioned, the current draw with 12V will be 1/2 of what a 6V is - so you have no problem with wire size. You will need to change the following items:

Generator
Voltage Regulator
Coil - and add the resistor. You will not have full 12V during start. Could be an issue.
All light bulbs
Flasher
Radio. I think a 12V radio will still tune with the built-in 54 antenna, but not sure.
Heater motor
Gauges will work as is. Not sure how accurate the gas and temp will be. The amp gauge will not show as much deflection, as current drain will be 50%.
Not sure about the clock. Probably does not work anyhow.

Starter will work fine on 12V. Spins like crazy. Just don't crank too long with it.
Horns and horn relay work fine on 12V - will wake the dead.
If you have powerglide, the start relay will be fine as it is only energized during start. (I think 54s had a relay, but is not a 904. Don't remember for sure).
The 2 fuses (heater and radio) should be changed to a lower rating in order to properly protect.
The circuit breakers built into the headlight switch are another issue. It will work fine on 12V, but will be over rated. It will still protect against hard shorts, but will not protect against overloads.
Make sure all the harness ground connections are very clean. The grounding configuration in these cars is horrible - to say the least.

One question - why do you want to convert to 12V?

Good luck,
-Dan-

[Michael S.]

Re: 1954 Wiring Harness Replacement

I think he needs the 53-55 6-cylinder harness since his '54 still has the 6 cylinder. I think the 55 V8 harness is physically different so it may not reach some 6 cyl engine related connections properly.

I believe, electrically, the harnesses would be the same whether 6 or 12 volts. Plus running 12 volts will mean that components will be drawing 50% less current through the wiring.

I'm not really knowledgeable on the early cars but jumped in 'cuz nobody else did at the time. Maybe some of the early C1 folks can jump in.

Rich

Rich,
Good thinking. I didn't even think about the fact that it should be a six cylinder car. I have a '54 that was changed to a 12V system a very long time ago. Whoever did it, changed everything to correct 12V pieces. The radio is even a correct '55 12V radio. It also has an extremely early 265 V8 which is why I forgot about the six cylinder. All of the wiring in my car seems to be the correct length without modifcation. I was typing before thinking it through.
Mike

[Richard M.]

Re: 1954 Wiring Harness Replacement

Rich,
Good thinking. I didn't even think about the fact that it should be a six cylinder car. I have a '54 that was changed to a 12V system a very long time ago. Whoever did it, changed everything to correct 12V pieces. The radio is even a correct '55 12V radio. It also has an extremely early 265 V8 which is why I forgot about the six cylinder. All of the wiring in my car seems to be the correct length without modifcation. I was typing before thinking it through.
Mike

Mike,

I assumed Kim has a 6 cylinder car, but we won't know for sure until we get a reply.

Does it look like your car has had the harness changed? I don't know which wires would be different for 6 cyl versus 8 cyl. Maybe just the starter wires are a little different in length, and maybe the ground wire(s) that attach to the engine.

Like I said I'm really a 53-55 dummy.........but I like to learn the nuances of these cool old cars if I ever run across one to work on. I have a good friend with a '54 he's restoring and am intrigued with it. e.g. I never knew the temp gauge was not electric, and I saw that funny looking fuse holder on the back of the fuel gauge that feeds the accessory fuse block panel.

Rich

[Michael S.]

Re: 1954 Wiring Harness Replacement

Mike,

I assumed Kim has a 6 cylinder car, but we won't know for sure until we get a reply.

Does it look like your car has had the harness changed? I don't know which wires would be different for 6 cyl versus 8 cyl. Maybe just the starter wires are a little different in length, and maybe the ground wire(s) that attach to the engine.

Like I said I'm really a 53-55 dummy.........but I like to learn the nuances of these cool old cars if I ever run across one to work on. I have a good friend with a '54 he's restoring and am intrigued with it. e.g. I never knew the temp gauge was not electric, and I saw that funny looking fuse holder on the back of the fuel gauge that feeds the accessory fuse block panel.

Rich

Rich,
No it doesn't. All wires seem to be the correct length. No splices or added connectors. Everything looks like it came the way it is, but you know it didn't come down the assembly line that way. It looks the same as my '55 which is why I answered the way I did.
Mike

[Robert I.]

Re: 1954 Wiring Harness Replacement

[QUOTE=Jim Lockwood (2750);671967]This and the advice to avoid restomod harnesses (like Painless, for example) is good advice.

What's wrong with the Painless harnesses? Was thinking about one for my 62.

[Richard M.]

Re: 1954 Wiring Harness Replacement

Bob, I'm certain Jim will opine when California sees the sun, but the reason I did not recommend:

I body-off restored a '59 years ago for a friend. He wanted me to use the Painless. I investigated. I'd have had to add terminals to ALL connections. The labor would've been tremendous. I gave him a ballpark number. He balked and we went with LL per my advice. It was "painless".

Unless your doing a restomod, I'd recommend stock.

Rich

[Jim L.]

Re: 1954 Wiring Harness Replacement

This and the advice to avoid restomod harnesses (like Painless, for example) is good advice.

What's wrong with the Painless harnesses? Was thinking about one for my 62.

There are some very good things about a Painless harness: It's made from high quality components. Every wire is marked as to it's function. You can make a harness with exactly the functionality you need, a valuable trait if you plan to add non-stock electrical accessories.

My son and I wired his flat-fender Jeep with a Painless harness and the results were very good. (Disclosure: I have many decades of experience fabricating specialty wiring.)

However.....

(You knew there had to be a "however...", didn't you?)

Every wire has to be run individually. Every wire has to be individually cut to length and appropriately terminated. If you are using consumer grade crimpers to apply terminals, you may or may not create reliable crimps. You may want/need to solder some connections. You will have to form the harness into bundles of related wires particular to your installation and zip-tie or somehow wrap these bundles to produce a neat final appearance.

Summarize it this way: It is a lot more labor intensive to create a functional, reliable harness using Painless products than it is to buy and install a plug-and-play reproduction harness.

[Dan D.]

Re: 1954 Wiring Harness Replacement

There are some very good things about a Painless harness: It's made from high quality components. Every wire is marked as to it's function. You can make a harness with exactly the functionality you need, a valuable trait if you plan to add non-stock electrical accessories.

My son and I wired his flat-fender Jeep with a Painless harness and the results were very good. (Disclosure: I have many decades of experience fabricating specialty wiring.)

However.....

(You knew there had to be a "however...", didn't you?)

Every wire has to be run individually. Every wire has to be individually cut to length and appropriately terminated. If you are using consumer grade crimpers to apply terminals, you may or may not create reliable crimps. You may want/need to solder some connections. You will have to form the harness into bundles of related wires particular to your installation and zip-tie or somehow wrap these bundles to produce a neat final appearance.

Summarize it this way: It is a lot more labor intensive to create a functional, reliable harness using Painless products than it is to buy and install a plug-and-play reproduction harness.

I will add to Jim's concern when using hand crimpers. My advise is - Don't. They are very unreliable. The individual wire strands move and relax over time, leaving the connection loose. They do not in any way mimic the quality of machine crimped terminals that commercial manufactures use. I always hand solder them any time I use these things.

Also, the blue/yellow/or sometimes red colored sleeving on the terminals that stores sell look hideous on our cars. The good part is you remove or destroy these colored things in the soldering operation. I always replace them with black shrink sleeving whenever I use them. They look much better, and once soldered, are 100% reliable.

My opinion/my experience.

Dan

[Chris S.]

Re: 1954 Wiring Harness Replacement

Kim
I use Lectric Limited for all my customers cars.
Buy the 54 harness and you will be fine with either 6v or 12 v
Chris
TiN Restorations
Plano IL