What should the voltage be at the coil on 46 6volt positive ground?

[G.M.]

Originally Posted by Big_Guys_baby

Tons of great discussion on this thread, thanks!

The serious voltage drop was happening at the ignition switch. Was able to hook up an
NOS switch body from carpenters and now showing little at all voltage drop compared to the over 2 volts from before. Also replaced the starter to solenoid cable with 6v correct as opposed to 12 volt skinny cable that had been on forever.

Showing now 6.2 volts at battery and 3.0 volts at coil with under dash resistor still running. the coil on the car is total mystery, but modern style. Tomorrow I am going to by pass resistor and put on IC7 to see how she runs, and more importantly hot starts.

If what you have is a true 3 volts at the ignition side of the coil with the points closed the engine will be boarder line in starting. The coil voltage should be in the area of 4 volts. At 3 volts to the coil when the starter is engauged the voltage will be below 3 volts. I found by changing resisters that at 3 volts the engine is hard to start and some times as you release the starter button the engine fires. This is due to the engine is still turning and the voltage to the coil go's up when the starter load is released. G.M.
What I meant by changing resistors was ones of different values.

[BUBBAS IGNITION]

Originally Posted by V8COOPMAN

"Yep"...I opened my big mouth, OR, "Yep"...I'm correct?

NOW I'm confused! DD

yEP YOU ARE CORRECT........

[Big_Guys_baby]

The diode bypass is only helpful if you are still running the external resistor correct?

[Stanley]

...I'm glad I found this thread. I have a 1946 Canadian Mercury Pickup with a original/stock flathead V-8. Same engine as the Fords.



Over the last couple years it got hard to start and seemed to run worse as time went on. To the point of only occasionally starting when cold and never starting when warm.... without a boost. replaced points, condenser... same thing. replace old wiring, same thing....
...So yesterday,with volt meter in hand I checked:
Battery sitting- 6.26 volts
at ign switch- 6.16 volts
at coil- 3.96 volts..........

This has a newer type 6 volt coil, and looking under the dash... resistor still hooked up.....
...So, bypass the resistor and at the coil now get 5.35 volts and at the distributor side of the coil, 5.0 volts.
The coil had been on there for ?? years, so replaced with new, and checked/cleaned terminals at switch.
now at the coil I get 6.02 volts and on the distributor side of the coil 6.02 volts...
...Hit the starter button .. fires instantly, runs smooth and louder... I run dual straight pipes...
...Test drive. Runs smoother, more power, the way it used to be....
Get home and let it sit for 5 minutes to see what happens when warm. Hit the starter button .. starts instantly...
Problem solved...
Thank you everyone for your in put here.. It worked out for me.
Stanley. ................

[Big_Guys_baby]

Stanley,

That truck is utterly and ridiculously cool! I ended up with basically the same issue. My dad had put a modern 6v coil with internal resistance on the car. I went through and rewired it, and replaced the fuse block/coil resistor under the dash. Once I start hunting the voltages because it wasn't running right, I figured i t out. Fairly simple, but makes a huge difference.

Next thing on my list is a carb spacer plate to help with the gas boiling issue.

[Stanley]

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...Did a 250 mile trip with the Mercury Pickup yesterday. Started fine cold, started fine warm. Ran like a top all day long... I sleep better at night now...
Stanley. ..............

[G.M.]

Originally Posted by Stanley

...I'm glad I found this thread. I have a 1946 Canadian Mercury Pickup with a original/stock flathead V-8. Same engine as the Fords.



Over the last couple years it got hard to start and seemed to run worse as time went on. To the point of only occasionally starting when cold and never starting when warm.... without a boost. replaced points, condenser... same thing. replace old wiring, same thing....
...So yesterday,with volt meter in hand I checked:
Battery sitting- 6.26 volts
at ign switch- 6.16 volts
at coil- 3.96 volts..........

This has a newer type 6 volt coil, and looking under the dash... resistor still hooked up.....
...So, bypass the resistor and at the coil now get 5.35 volts and at the distributor side of the coil, 5.0 volts.
The coil had been on there for ?? years, so replaced with new, and checked/cleaned terminals at switch.
now at the coil I get 6.02 volts and on the distributor side of the coil 6.02 volts...
...Hit the starter button .. fires instantly, runs smooth and louder... I run dual straight pipes...
...Test drive. Runs smoother, more power, the way it used to be....
Get home and let it sit for 5 minutes to see what happens when warm. Hit the starter button .. starts instantly...
Problem solved...
Thank you everyone for your in put here.. It worked out for me.
Stanley. ................

You may get good starting with 6 volts to the coil but your points won't last long. Make sure the coil volts is read with the points closed, the voltage at the coil will read close to battery voltage with the points open. G.M.

[Stanley]

I used the STANDARD T Series UC14T. Stamped on the Coil are the words 6V No External Resistor Required.
Stanley. .........

[G.M.]

[QUOTE=Big_Guys_baby;880845]Hey Barners! I am in finishing stages of getting my 1946 Ford Business Coupe on the road for real. Still having some intermittent electrical issues and hot starting problems. Distributor was just rebuilt by Bubba's, all the wiring has been replaced. New brushes on generator, lots of grounds throughout system.

The coil has been on the car for a few years and I have no clue where it came from or its specs. I am getting 6.3 volts at the battery, 6.2 volts at the ignition switch, and I am getting 2.9 at the coil. It is running an external resistor under the dash. I haven't done a voltage test at the coil while cranking or tested the resistance at the coil. I picked up an IC-7 coil from napa, thinking about bypassing the external resistor and putting that on to see if I get better starting and running.

Car is still 6 volt positive ground.

To answer your question. On a 6 volt Ford coil with a fully charged 6 volt battery at 6.3 you should have 6 volts at the coil with the points open and in the area of 4.0 with the points closed. Higher than 4 volts burns the points and below 3 volts will be hard to start. Lower voltage at the coil indicates, low battery, dirty ignition switch, bad wiring, bad battery ground, bad battery connections or small battery cables. Small or 12 volt battery cables used on a 6 volt system drop the 6 volts much lower when the starter motor is running. This drops the 4 volts seen at the coil to below 3 volts making it hard to start. It will start sometimes just as the starter button is released. At this instant the engine is still turning, the voltage raises to the coil and it fires. This is also the reason if you coast for a few feet and pop the clutch it will start, you get the full battery voltage to the coil without the load drop of the starter. I don't know about or get into all of the brand X round coils with adaptors mounted on the old Fords. When you get into these adaptions or abortions it's hard to trouble shoot, with the stock type parts are repetitive and problems easy to diagnose it's the same every time. The stock Ford coils had problems from when these cars were new when they got hot. Skip Haney in Florida has rebuilt over 20,000 32 to 48 Ford coils over the years with maybe 20 or 25 that had any problems and he repaired them at no charge. The reliability comes from modern insulation covering the wire and between layers that stand much more heat. This is not an add, Skip gets about all the work he can handle from word of mouth between Ford owners. This is to inform new owns and newcomers to the forum the most reliable way that is guaranteed to solve the coil problem.
I live in SW Florida and it's over 92 degrees everyday and I drive my 39 a lot. Drove it 5 days in a row late last week and over the week end and never had a hint of not starting on the first turn of the engine due to ignition. Gas is another story which I will post on later. G.M.