No Spark - Advice Needed

[CFT]

My '31 Coupe is not getting spark and I haven't figured out why. I'm trying to get the car running as there is a car show in my hometown and my son wants to enter the car in the show.

My cheap repro plastic wire terminal box melted last year. I don't know how it happened. I replaced the terminal box with a good original and put in a newly restored popout switch. All wires look visibly fine. I'm getting current from my popout to the distributor housing but no spark at the points.

How do I test the points, condensor and coil? I suspect it's one of those items. I suppose I could replace these items but I would like to figure out what's going on here.

Any advice from some of you experts would be appreciated.

P.S. Can anyone recommend a book or video on how to check out the ignition system?

[MCHinson]

Les Andrews is probably about the best expert on this issue so...

I took the liberty of stealing this from the Model A Ford Club Website's technical Q & A Page:

Answer:

Sounds like you have a problem in the ignition circuit. Here are the checks to make:

Yellow wire connected from post on starter switch to terminal box post (post on passenger side of terminal box).

Ammeter (-) side connects to passenger side post on terminal box.

Ammeter (+) side connects to driver side post on terminal box.

Black wire connects from driver side post on terminal box to coil (-) terminal.

Red wire connects from coil (+) terminal to ignition switch.

Yellow/Black wire also connects from driver side terminal box post to the cut out terminal. That completes the ignition wiring except for the ignition cable and distributor plate.

Here is a voltage check of the circuit:

Connect the (+) side of your volt meter to a good ground point on the engine or frame.

Touch the (-) probe to the passenger side terminal box wing nut. Read 6 volts.

Touch the probe to the driver side terminal box wing nut. Read 6 volts.

Touch the probe to the (-) terminal on coil. Read 6 volts.

Touch the probe to the (+) terminal on coil. Read 6 volts.

Place a piece of paper between the point contacts.

NOW TURN IGNITION KEY ON.

Touch the probe to the end of the points arm, read 6 volts.

Remove paper between points. Open and close points and look for spark each time points open, (no spark means bad condenser, replace condenser).

. If points are sparking then disconnect the coil center (high tension wire) from the distributor cap (leave connected at distributor end). Place the free end of the coil wire about 1/8" from one of the engine head nuts. Crank the engine over with the ignition key on. There should be a bright blue arc from the coil wire to the nut (ground point). No arc means bad coil.

Having said all of that, there are several things to check for. New condensers can go bad and new coils can go bad. But I would first look for something that may be shorting the circuit or causing an open in the circuit. Some of the other things to check are: Bad Ammeter. If ammeter has open circuit, all voltage is lost to the coil. You probably burned the wiring up because of loose connections on the back of the ammeter, or missing rubber grommet through center of terminal box, causing the ignition cable to short against terminal box posts, causing large current draw to burn wires. Do not screw ignition cable into the distributor too far. It can short out if screwed in too far. Make sure all nuts on the terminal box posts are tight. Also the two rivets on the bottom distributor plate sometimes get loose (especially on the reproduction plate) and short out the bracket it attaches. -- Les Andrews, 1998 Technical Director

Hope it helps!