Coil wire gauge size

Jakno

Jakno

Senior Member
I have a 1937 59AB engine with 6 volt system and original helmet generator, distributor and coil. Having all the usual heat related problems with starting my 35 pickup. Cold it starts fine, hot starting it's like a 1/2 charged battery.


I am replacing the coil with a new Bosch coil. Not sure I have the right sized wires from the coil to the distributor and switch to coil. They appear tp be 16 & 18 ga wire.


Might this be part of the starting issues I'm having ?
 
Being a coil draws max 5amps and it´s a short wire the voltage drop isn´t going to be bad with one size smaller wire.
Badly contacted connectors would be more of an issue.
The 18 gauge would take 3 times the load of a coil and be within it´s load range.
 
16 AWG would be what Ford used for the ignition circuit less the high tension side. The current draw is controlled by the ballast resistor in the circuit on the older V8 cars. The circuits providing transfer of power from battery to bus and for the generator charging system are the largest harness type wires in the 6-volt systems. The head lamps generally use a larger gauge due to the current needs but most other light duty circuits are 16 gauge.

A 16 gauge wire is generally protected by a 10-amp fuse but most of the older cars used circuit breakers. The circuit breaker rating for a 16-gauge wire is 15-amp since they are a bit more sensitive than a fuse wire. You can use a smaller fuse rating but this is the largest rating that should be used for that wire size.
 
Jakno said:
I have a 1937 59AB engine with 6 volt system and original helmet generator, distributor and coil. Having all the usual heat related problems with starting my 35 pickup. Cold it starts fine, hot starting it's like a 1/2 charged battery.


I am replacing the coil with a new Bosch coil. Not sure I have the right sized wires from the coil to the distributor and switch to coil. They appear tp be 16 & 18 ga wire.


Might this be part of the starting issues I'm having ?
Click to expand...

Jakno, for definitive answers, it would be helpful to know exactly what you're working with:
A 1937 engine is not a 59AB, and a helmet refers to a distributor, not a generator.
Is the helmet distributor original to a '37 engine, with the coil on top? If so, then you have an adapter plate to convert to the Bosch coil?
Is the distributor original to a 59AB engine, with the coil mounted remotely from the distributor? Is there a resistor mounted with the coil? Are you running your ignition wire through the original resistor mounted above the steering column inside?
Can you explain your half charged battery description further?
 
I say if its turning over like a half charged battery, just that alone is sucking a lot of
juice starving the coil. Bad starter bushings dirty armature, worn brushes, most important is dirty starter end plates that causes poor ground, such as the brush end plate made
from aluminum does not get along with steel - it gets that white stuff corrosion or even
paint - those ends as well as the housing must be clean. I have 5 = a car and 4 trucks
all 6 vts up to the biggest 337 in a F8 and all start as 12 vts instantly. oh a 23 Ford too
that wipps right over on 6 vts. So Jakno just try a jumper wire battery to coil , now try
it. Another thought, if you were to remove spark plugs hit the starter it should whipp and spin right over, if not I point to starter problems sam
 
Gentlemen, thanks for helping me out even when I don't know what I'm talking about. attached are pictures which should be much more valuable describing what I have for a motor, generator, coil and distributor.
Again the problem is hard to start when hot and act's like the battery is dying.
I do have a new 8 volt battery which I have tried and same results as the 6 volt battery.

Thanks for your interest and help
 

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The 1942 crab cap distributor conversion was common in the 60s & 70s due to lack of original type spares for the 46 thru 48 models. They generally used a Ford bakelite type coil though. The can type coil was also an addition.

If its turning over slow when hot then it may need either a new starter cable or an overhaul of the starter (maybe both). The condenser can die when it gets hot so that's a possibility. The carb may have an internal leak that's causing it to flood after shut down when hot and require the pump to refill the bowl too. Both of those can cause hard starting. An old coil can also break down when it gets hot so that's another maybe. How long since the last time the distributor was serviced? The advance unit may be all gummed up in there too. That stuff needs to be clean & well lubed to function as it should.

Start with the easiest thing first and go from there.
 
What is on the battery for the power and ground cables? If they are the normal auto parts store variety they are most likely not a large enough gauge. 6 volts require a larger gauge of wire than 12 volts systems. Grounds are also important, make sure the grounds are clean, bare metal and I would apply a thin coat of grease to keep them that way.
 
Check to make sure everything has good clean grounds. Grounding is critical and your symptoms lead me to believe that poor grounding is part of your problem
 
Thanks, I'll pull the starter off and go thru that and while it's on the lift I can check all the grounds & connections. I do have good sized copper ground cable, # 2 stranded I believe.


Thanks for the help
 
Get a Voltmeter preferably an analog one.
Scrape a clean connection at the engine so you can measure betwen that and the positive(earth) connection at the battery.
Have someone crank the car while you measure.
The rading you get is the voltage drop in the grounding cables...will tell you the condition of it.
Better to analyze a bit before starting to swap things....i´m cheap...
 
Jakno said:
Thanks, I'll pull the starter off and go thru that and while it's on the lift I can check all the grounds & connections. I do have good sized copper ground cable, # 2 stranded I believe.
Click to expand...

While you have the starter off, make sure that that copper lug is PROPERLY TIGHT on that wire. Also make sure that there is bare, shiney metal (NO PAINT) on both starter and pan surfaces where they bolt together. DD
 
Check that starter wire connection. Looks like a lot of bare wire at the lug connection.....Mark
Edit: I think V8CCOPMAN already mentioned this in his post. I think I need more coffee!!!
 
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Many folks prefer -0- American wire gauge for the starter cable rather than 2 awg for 6-volt systems. It doesn't have to be the flexible welding cable but welding cable will work. The old ground cables were the big 1 1/8" to 1 1/4" flat braided tern plated copper strap type back in the day but they need to be big what ever type conductor is used.

8-volt batteries can't be maintained to charge with the 6-volt system and adjusting a regulator for 9.1 to 9.5 volts in a PITA. 6-volt works well enough when properly maintained.
 
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