I am getting ready to install BASIC wiring to perform initial test start on my project. (1954 235ci, 12 volt alternator, 6 volt starter, battery in original location under passenger seat floor.
When I get to thinking about specifics, it is amazing to realize how little I am sure of!
Jerry has approved of my (very messy) schematic of what I intend to do. (Thanks Jerry! Now it is up to me to follow the schematic and not let the magic smoke out!)
From what I have read on the forum, I expect to use 4 gauge stranded copper wire from battery to grounds and from battery to starter.
For battery terminals where it would be handy to terminate more than one wire/cable what is a good solution? (I am thinking of grounds to frame, engine and cab…and the positive connections to the starter, ammeter and incoming from the alternator.)
From alternator output to battery, 6 gauge stranded copper?
For the rest of the basic wiring to run the engine, would 10 gauge stranded copper be enough?
For the wires that I run, what is a good source for terminals? (Where did Radio Shack go?) Are crimp terminals good enough, or should I consider solder-type? Or crimp and solder?
Once I am convinced that the engine in this project will run, I expect that I will be purchasing a basic 12 circuit wiring harness kit as suggested by Bartamos (one year and one day ago!).
When I purchased my project, I was not aware that this forum existed…now I wonder how much more lost I would be without it!
Thanks All!
Nick 1940 KC Model 1/2 Ton Pickup Project (with '37-'39 Bed and what we think is a '42-'46 Frame) Taos, New Mexico
Assuming you are not adding any big time electrical load like A/C, a huge sound system or low-rider type hydraulics ....
I'd run larger than 4 gauge wires for the battery cables. #2 or even 0.
I'd run only the battery + to the stomp switch and stomp switch to where ever else you need you need "hot all the time" voltage, which in stock wiring is just the ammeter + and on to the horn. Run #6 wire from the alternator output to the stomp switch. I'd use a 3 wire (not 1 wire) alternator with the "sense" wire hooked to somewhere convenient past the ignition switch's "run" terminal.
These wire size are oversize, but you'll never have to worry about them being undersized.
Proper crimping is sufficient without soldering. And heat shrink tubing is your friend.
Wire size table attached.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
After living on a boat for a couple of years, I have a decent crimper for smaller gauge wire, but what should I use to terminate #2 or 0 gauge cables use if I don't purchase pre-made units?
Also, what is a good source for terminals to use with 6-10 gauge wires? (Is there much quality difference between brands?)
Nick 1940 KC Model 1/2 Ton Pickup Project (with '37-'39 Bed and what we think is a '42-'46 Frame) Taos, New Mexico
I use #0 welding cable for battery hot and ground cables. It's more flexible and has many more strands of wire than regular battery cable. #6 or #8 wire is plenty for charging system wiring and body to frame and bed grounds. I like to run the battery ground cable to the bell housing or a starter mounting bolt to minimize the number of connections that carry starting current.
This tool and a 3 pound hammer does a good job of crimping battery cable terminals:
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
I also keep a good supply of various diameters of heat shrink tubing to reinforce those crimped connectors and wire splices. Shrink tubing is able to compress to half its diameter when activated with a propane torch, a lighter, or a hot air gun. When making splices in a wire bundle, I prefer to wrap the wire strands together tightly, solder the connection, and cover the splice with shrink tube. It's a lot less bulky, and is less susceptible to getting loose than a crimped splice. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Get a good ratchet style crimper and you should be good to go. Mine is made by AMP - not cheap but at least 30 years old it's been a good investment.
For the battery to ground and starter connections, I buy the off the shelf cables at the local auto parts store. Ready to go; no cutting or crimping. Neat and time saving.
I'm using the common 63 A 10SI alternator. I use 10 gauge from ammeter to the alternator; works fine. Lots of previous discussions on this forum on how to connect alternator up so engine will shut off when you want it to.
Battery to starter, As big of cable as you can afford, welding cable is flexible and works just as good. 1/0 to 00, 4 gauge is not big enough.
Starter to coil, 18 gauge minimum, 14-16 gauge if you have it. 10 gauge not needed. Alligator clips will get the job done, not a lot amps here.
Alternator or generator, 10 gauge minimum, 4 gauge if running a lot of accessories, 8 gauge is probably about right. No real need to wire up the alternator unless you plan on a lot of run time.
I'm on the side of, you can never have to big of a wire. But with that comes routing and connectors, the bigger the connector the more they cost.
I strip the plastic off crimp connectors, add shrink sleeve to the wire and solder all my connectors on, then I shrink sleeve over them. To me they look more professional.
I made my whole wire harness from a harness I stripped out of a school bus. It had all numbered and colored wires 10 to 16 gauge wires. Its big and heavy duty, but in the last 26 years I have never had a light flicker or the truck never start.
On my engine test stand I built for V8 engines, it has 000 battery cable coming off a 950 cca battery. It has never failed to start a new engine. I use alligator clips on the wire ends for easy hook up and mechanical oil and water gauges.
Gauge panel for test stand I built. Pull switches for Ignition and fuel pump, push button for starter. mechanical water, oil gauge, vacuum gauge for tuning, tack for rpm. Fans are from a wrecked school bus under-bus A/C condenser. It takes all four to keep a new engine cool running at 2500 rpm for 30 minutes. I have since turned the radiator around so the air from the fan hits the engine, they used to blow out away from it. The air across the headers helps cool the whole thing down. I always have a water hose close by for added cooling if needed. Once the engine starts, I do everything I can to keep them running, tune on the fly. Once the break-in is done, I can slow it down and set the adjustments.
The fans run right off the battery with 8 gauge power and ground, two fans per switch. With all four running you can hear the engine slow down from the drag on the alternator.
Many are sold in sets, often with an extremely cheap crimper included. Connectors can be very thin with shiny plating, easily bent. Plastic sleeve may split when crimping. It's frustrating when a male and female connector don't fit properly.
Suggested wire sizes are helpful. It makes sense to me to go perhaps a bit oversize with the wiring.
I have a decent quality ratcheting crimper tool.
I have ordered some Pico terminals.
I am setting things up for this test run with temporary ignition switch, oil pressure, water temp, and voltage gauges on a panel right next to the engine, although I don't expect to run it for long at all with this temporary setup.
(This project came to me with the story that it was a crate engine. The block and head were cast on the same day in late '53. But inconsistencies in paint colors have me thinking that at best, it has been rebuilt.)
Nick 1940 KC Model 1/2 Ton Pickup Project (with '37-'39 Bed and what we think is a '42-'46 Frame) Taos, New Mexico
I just started to use U shaped crimp connectors, that look like factory made crimps. Once sleeved with heat shrink they are very thin. You need crimpers specifically made for these connectors and it took a bit of a learning curve before I consistently got good crimps. I believe they are superior to barrel crimps as they crimp, not only the bare wire, but the cable too. I also bought ring and spade terminals for my upcoming rewiring job.
Phil Moderator, The Engine Shop, Interiors and Project Journals
1952 Chevrolet 3100, Three on the Tree, 4:11 torque tube Updated to: ‘59 235 w/hydraulic lifters, 12v w/alternator, HEI, PCV and Power front Disc Brakes Project Journals Stovebolt Gallery Forum
I've used the same connecter as Phil shows above with non-ratcheting crimpers, they work really good on the smaller wire gauges. Being a school bus mechanic for 30 years one gets good at wiring, we are always adding camera's, radios, tablets, gps, etc..... I have a couple boxes of leftover connectors and harnesses it pick from.