No spark at distributor

[cp5491r]

Help please- I'm not good at electrical.
1930 Tudor:
I've got 6 volts at the passenger side of the coil and only 0.3 at the driver's side post of the coil with the key on. Is that correct? No voltage at the end of the wire that goes into the top of the distributor. I've pulled the gauge panel and nothing seems to be shorted out. Am I missing something simple?
Thanks.

[Patrick L.]

Remove the secondary [ high tension] coil wire and hold it 1/4" from a good ground. Turn key on and push on the starter rod, as the engine turns over look for a good spark.

If no spark, remove cap and rotor. With points open there should be battery voltage. When points close there should be no voltage.

If no voltage with points open then look for the problem from the points arm back thru distrbutor contact, coil and key switch.

If voltage at points arm when closed, clean points contacts and make sure fixed contact is properly grounded.

Try these first, if they don't work let us know and we'll continue on for a problem like the plate wire.

[cp5491r]

Thanks. I'll try these ideas.
It's odd. It started yesterday. I ran it for 5-10 minutes and shut it off. Then it wouldn't run again.

[BILL WILLIAMSON]

Loosen your distributor cable 1/2 turn, & see what happens.
Bill W.

[cp5491r]

I've got the newer distributor plate too but I guess there could be a short there. Headed to garage to check it again.

[H. L. Chauvin]

Sponsored Links (Register now to hide all advertisements)

FWIW:

One (1) suggestion to try to assist any Model A owner with their future fears of the Model A Electrical Unknowns ....... and one (1) suggestion to try to assist Model A owners to actually "see" the simplicity of a Model A Electrical System:

1. First, try a Forum "Search" for a Model A "Wiring Diagram" if one does not have one.

2. Knowing that one can read a "human-drawn" map with lines representing "continuous" highway routes ....... likewise one can easily read a "human-drawn Model A wiring diagram" which is nothing more than is a "human-drawn" map showing routes of "continuous" wires in lieu of routes of "continuous" highways.

3. The human mind can easily find a "continuous" route connecting Plattsburg, New York with Key West, Florida ....... even after said route traveled "continuously" through many towns.

4. Likewise, with a multi-meter or test lamp, one can easily start at a Model A's source of "energy" ....... i.e., the battery ...... and follow the "human-drawn" diagram of "continuous" route or routes with continuously monitored "energy" to the distributor.

5. If at one point, or after one connection, no "continuous" energy is found, investigation is required ....... if it were a highway, would it be a bridge out, highway surface removed, a pile of trash on the highway ...... with a wire it could be a broken wire, a dirty connection insulating continuous energy flow ..... or whatever.

6. Similarly, this is why 4 year old children can have fun playing games on a cell phone & we cannot ...... no educator convinced them that cell phones are difficult ..... and no educator convinced them that they needed a Degree in Electrical Engineering in order to operate a cell phone.

7. After seeing 4 year olds on our cell phones, no doubt it is a good idea at times to shed our incorrect modern education, to think young again, unlearn a few things, and start from scratch ...... just simple maps.

Hope this helps.

[Mitch//pa]

here is a diagram if you dont have one

[cp5491r]

Thanks for the input and diagram.
There was no spark and 0.4 volts with points open. I cleaned the connections at the terminal box, and adjusted the cable into the bottom of the distributor. I then had spark and 6 volts with points open. Car started and I ran it several minutes but the ammeter wouldn't show a charge even with revved engine. I shut off the car and tried to start it again and the same problem arose- no spark and virtually no charge when I opened the points.
No amount of screwing the cable into the bottom of the distributor more or less would produce voltage at the points. SO- I'm thinking that the cable from the ignition switch to the bottom of the distributor has a broken wire in it. Reasonable???

[Mitch//pa]

how about the lower plate wire. or connections of the plate wire grounding int.. moving the advance lever moves the plate wire

another thing to ck is if your running an aftermarket type igntion switch is to insulate the terminal legs from grounding on the gas tank.. back the dash panel off and try

[Patrick L.]

Yep, what Mitch said. Also you could remove the primary lead into the distributor and see if its bad. Its somewhat common for the insulation to go bad and short to the outer casing usually right where they screw into the housing.

[H. L. Chauvin]

FWIW:

If one has a Bratton's Catalog, (any year), Bratton's always showed an Ignition Switch Test Diagram showing how to test the Ignition Switch connections and grounded cable connections at the distributor, with the ignition switch "ON" and "OFF" with:

1. The Ignition Switch marked (A); and,

2. The grounded Armored Cable marked (B); and,

3. The Insulated Wire in the cable, leading to the distributor, marked (C).

Might help someone some day.

[Tom Wesenberg]

An ignition emergency jumper is a very handy tool to carry in your car.
Snyder's lists it as A-11576-RK3 for $14.95.

The fact that you have .3 or .4 volts on the ground side of the coil tells me you have something grounding out. As mentioned, the repro key is often the problem when it's contact rubs on the gas tank. If you have an original popout, then the wire inside has 85 year old insulation and has likely worn and the wire is grounding. If the .3 volts is with the key on or off, then I'd say the problem is most likely right at the key switch.

Also, if you have a slant pole coil, be sure it has insulating washers on each of the primary terminals, so it doesn't short to the case. The hardware order is: insulating washer, flat washer, lock washer, hex nut, then the wire terminal and barrel nut.

[mhsprecher]

I was "helping" a fellow club member last week with a similar problem. No spark from coil. I was helping him during a lunch break and had to get back to work, but I am not the best to diagnose electrical problems. Something I need to brush up on. I enjoyed reading this thread and will look at Bratton's catalog. I need to place an order tonight, anyway. :-)

[Mike V. Florida]

Originally Posted by cp5491r

Help please- I'm not good at electrical.
1930 Tudor:
I've got 6 volts at the passenger side of the coil and only 0.3 at the driver's side post of the coil with the key on. Is that correct?

With the points closed, yes points open like with a piece of paper between them, no.

No voltage at the end of the wire that goes into the top of the distributor.

This is the high voltage side that delivers the voltage to the points.

I've pulled the gauge panel and nothing seems to be shorted out. Am I missing something simple?
Thanks.

This may help,

https://www.fordbarn.com/forum/showpo...87&postcount=4

[cp5491r]

Thanks for the additional ideas and the drawing!
I haven't had a chance to get back to the storage unit to check the lower plate wire grounding out. I wish I was retired and had more than an hour or so at a time to work on the cars

[katy]

No voltage at the end of the wire that goes into the top of the distributor.

This is the high voltage side that delivers the voltage to the points.

High voltage goes to the spark plugs.

[Mike V. Florida]

Originally Posted by katy

High voltage goes to the spark plugs.

That was a stupid mistake on my part. Thanks for the correction.

[katy]

We all make mistrakes once in a while.

[cp5491r]

I am frustrated on this one. With switch off, I have voltage from starter to both sides of coil. Ampmeter discharges when I try the horn. Took distributor plates (top and bottom) out to look for shorts and didn't see any issues. Replaced the wire from switch to distributor, thinking it might of been shorted out inside the cable, still no spark at the points.
What am I missing?? Thanks.

[Mitch//pa]

switch on points closed you should have power to one side of the coil
switch on points open you should have power to both sides of the coil
make sure your repo switch legs are not touching the metal gas tank or youll get false readings.
loosen the dash to let it hang away from the tank