'spent a few minutes this morning sketching up a wiring schematic for a project I'm working on. not at all electrically proficient but can move a mouse in CAD so that's the tool chosen for the sketch work.. anyway, if I had another few sets of eyes to review my work I'd feel bit more comfortable going to install. a few notes; '57 Chevrolet engine, with stock type; start, charge and ignition systems '48-'50 Ford truck light switch unknown dimmer switch, horn relay, fuel sender (Tanks?) simple two pole on/off ignition switch Ford starter button mid to late fifties Stewart Warner aftermarket gauges, mechanical oil pressure and water temperature. Ammeter not show connected yet, not sure if it will be used and frankly not sure exactly where it would be inserted, in series in the 10 gauge wire between starter and regulator? no turn signal switch at this time. edit: image removed to avoid confusion
Very nicely done! Suggestion.....consider putting a hi amp (50/60) fuse between the starter battery post and the ignition switch batt post. That way, if there is major catastrastroke (short) it should keep the rest of the harness from letting all the smoke out. Ray
Good suggestion, except that it would be attempting to protect 14 gauge wire with a fuse that is too high amp capacity. 20 or 30 amp might be more appropriate. But I'm pretty confused by the wiring for the coil, starter button, etc. Things don't seem to be connected where they ought to be connected. For example, you seem to have the starter solenoid having two connections, when it really has three (Big lug for the battery, S for start, and R for resistor bypass). And how does the power get to the Constant on the fuse panel? from the Starter Button?
Staring at it some more, I guess I was mistaken in how I read the diagram..there's a wire connection that looks like a jump where wires cross. There are different notations used on different schematics, and it wasn't clear to me what notation you are using. So the only real issue is the two wires on the starter that seem to go to the same place, but if you understand they go to different terminals, then it should be fine. The ammeter...if you were to use it, run a #10 wire from the big terminal on the starter to one side. Run the two wires (#10 and #14) that connect to that starter terminal, to the other side of the ammeter instead of to the starter. You have to wire it this way so the ammeter will show current going into and out of the battery. Which is what we expect an ammeter to show.
thanks Jim, here is my train of thought the starter solenoid has the large lug to accept the battery cable and the 10 gauge wire from the regulator and would also get a wire to power the ignition switch per the sketch. the other post on the solenoid is connected to the starter button and will get a wire to the coil to bypass the resistor on start up, also per the sketch. there is no third post on this solenoid (other than the heavy lug to the starter itself) I have a few wires strung, battery cable and wire from starter button here..
If there is no R terminal on the starter, then you cannot connect the coil to the starter to bypass the resistor. The way you have it designed now, it will be powering the starter when the ignition is turned on, through the ballast resistor. So just leave out that wire from the starter to the coil. It should still start ok. If you have trouble with it, you could try to find a starter solenoid with the three terminals, or use a relay to bypass the resistor when starting. I doubt it will be necessary, though.
The original 57 chevy ignition switch had two different terminals for ignition, and it was used to bypass the resistor. I think they went to the R terminal starting in 1958.
So what’s the fuse panel getting power from? Looks like #10 ga wire but losses that at the ign to a #14ga. that is actually the feeder
In the past, I've been advised not to zip-tie the plug wires together as in your photo. As the wires age, arcing between wires is difficult to see. Just my 2 cents. The technology may have changed with the onset of 8 and 9mm wires. .bjb
Yeah, the plug wires...but that's a subject for another thread! Let's get it wired up and running first
ok, here is the sketch with the recommended changes, also with the 30 amp fuse added per above suggestion I felt the 30 amp fuse in the fuse block to the horn was redundant so it was not used yes the zip ties on plug wires may go away.. edit: image removed to avoid confusion, thank you
That looks good. I'd put the fuse in the wire from the big terminal on the starter, the closer to the starter it is, the more wire it will protect. Although they never had them in cars as original equipment back then.
ok, hopefully this is the last version, thanks for all the input! Edit: image removed to avoid confusion
I'm using Autodesk AutoCAD 2016 with Carlson Survey 2015, my employer gave me my laptop, programs and licenses with eternal updates when I retired.. almost three years ago now I try to break it out every so often to try to remember how to use it. I have no electrical specific programs, this was all done from scratch. my programs are more to construction layout, building survey and architecture
Paul, What is your generator (or alternator) output rating? Reason I ask, it seems to me that any current to the battery, as well as from the battery, goes through the fuse you added and is the reason I suggested a higher amp fuse. Squirrel is correct that the wire size in the first diagram was too small for that size fuse. Though I should have pointed that out, I did not, assuming a wire size upgrade would be included in the mod. If you are using a relatively low output generator, and few high draw accessories will ever be operated simultaneously, the 30 amp fuse would be okay. But, now is the time to consider future upgrades while you are stringing wires..... Ray
In the event the owner (or subsequent owner) does want to add something that needs a little more juice could the way it's drawn now handle a higher amp in-line fuse?
Yes, you could probably get by with a higher rating fuse...but #10 wire with a 30 amp fuse is pretty common.
Two suggestions … Use a coil with internal resistor, eliminating a few feet of wire & extra parts. Feed the starter button from a battery source, not the switch. You'll be able to bump the engine over w/o firing it .
thanks, but the owner was hoping to use the old wire wrapped resistor and the starter button is wired to the hot side of the ignition switch just for that reason.
I got about halfway into install and decided to make a few changes to the drawing, mostly to better show object placement, add the turn signal switch and basically tidy things up a bit.. after the wiring is all done and tested I intend to do one last version of the drawing to show wire color. and any other stuff that may change along the way. and finally give a copy to the owner for future reference.
Nice drawing, but I'd bump some of the wire sizes up. I like to see #10 to the light switch and #12 to the headlights (to reduce voltage drop and insure bright lights), and the output wire from the generator to the regulator should be #10.
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