'69 Dart Custom - Not Sparking

[morsim]

Hey all!

Currently working on a 1969 Dart Custom that has a cranking engine but the ignition coil doesn't seem to be sparking so it doesn't actually run.
I bought a new coil but I'm just not very confident in the way it's wired up.

I've currently got two things connected to the negative coil terminal:
- The ignition distributor
- Some kind of piece that looks like the ignition condenser which, on its other end, is then connected to the chassis via one of the two screws that hold/mount the coil

The positive coil terminal has some wire connected that only shows power when the car is in accessory/run mode (key slightly turned). But of course, even fully turning the key just cranks the engine without starting since no sparks.

Can anybody kindly share some knowledge as to what may be going on here? I suspect it has something to do with my coil connection, but I can't seem to prove it. Perhaps some thorough wiring diagrams would help...

 

[67Dart273]

OK, the strange device on the coil negative is a radio noise suppression capacitor/ condenser. It belongs on the coil POS connection

You want to determine a couple of things.

1...The run voltage you checked goes through the ballast resistor to the coil. Now, that is ONLY hot with the key in "run." THAT goes COLD when you twist the key to "start."

2...SO HOW does the coil get power in "start?" There is a second contact on the ignition switch, called IGN2. That is hot in the "start" position, just like the "s" "start" terminal. THAT IGN2 --brown wire--is fed out through the bulkhead to the coil side of the ballast. So with the key twisted to "start" the coil should get full battery voltage.

3...Distributor, points, and condenser: It is important to determine if the points are opening and closing, and more important, are actually electrically making and breaking the circuit. One way to do that is to put a lamp/ meter on the coil NEG and turn the key to run. Bump the engine over by using a screwdriver to short across the two large bare terminals of the start relay. The meter/ lamp should go from battery voltage -when the points are open- to very low, no more than maybe 1V when the points close, as the engine is bumped around.

If that is happening, "rig" a test gap like a spark checker or opened up spark plug on the coil tower to ground. You should see good hot spark there

IF you have power for certain, IF the points are acting as I described and yet you still do not have spark, the trouble is most likely either the condenser or the coil

UNLIKE nonsense around the web, you CAN NOT really test a cap with an ohmeter. You really need a device which will test high voltage leakage. Buy another condenser and hope for the best. They are cheaper than a coil, and of course if that is not the trouble, then the coil is the thing.

 

[morsim]

Ok, got it. I moved the new condenser to coil positive along with the other "run" wire. I have the distributor wire connected to coil negative only now.

When the ignition is in "run", I'm getting 12v on both the POS and NEG coil terminals. However, if I connect the coil NEG to chassis, then I get a low-ish voltage on the POS coil terminal (about 7 volts) but no voltage on the coil NEG terminal.

With my new ground cable connecting the NEG coil terminal to chassis, I crank the engine, but no spark and no voltage/test light-up on the negative either (shouldn't that be pulsing?).

Without my new ground cable connecting the NEG coil terminal to chassis, I'm seeing 12v on both coil terminals when in "run" AND crank.

Any ideas?

P.S. According to this YouTube video, the coils terminals should NOT be getting 12v when in "run", but instead some lower amount, because of the ballast resistor - which is why I  tried the makeship coil-to-chassis connection. Is that correct or is something different here? He also speaks about a "badly grounded ignition module" that could cause the coil's voltages to stay at 12v. Does such a thing exist in this car?

 

[morsim]

Turns out it was a problem inside the distributor. The connection point/contact that makes and breaks the circuit was corroded and so there was no power being provided to the spark plugs. Used the rigged sides of a flathead screwdriver to shave/clean off the corrosion from both sides of the connection (and another flathead to hold the contacts apart).

P.P.S. I didn't end up using my makeshift coil-to-ground connection. All worked fine with the connections the way @67Dart273 clarified. Thanks!

 

[morsim]

Obligatory shot - she's back on the road after 30 years in the garage!
Next step is a well deserved wash 'n shine.