Ford Thunderbird Ignition Wiring Diagram
Originally posted by kevin_tbird View Post
As background this engine was... broken in on a stand,
Piston ring break-in can only be accomplished while the engine is UNDER A LOAD.
Originally posted by kevin_tbird View Post
...However, the lack of a resister should not be a problem for starting/testing the vehicle - right?
That's right. Some racers NEVER use the resistor. It just means the points will need to be changed more frequently because they dump more current. At high engine speed, the coil never gets enough time to completely fill, anyway.
Originally posted by kevin_tbird View Post
I have full battery voltage at the + side of the coil... When cranking the voltage drops about 6v which is within spec.
The ONLY reason your voltage should drop is because your battery is weak and it is dropping half its voltage.
Originally posted by kevin_tbird View Post
After disconnected the pink wire the brown wire from the starter solenoid does NOT carry battery voltage to the coil. When cranking the engine it generates a little more than 2v. After cranking the voltage drops slowly. I'm not sure how far, but down to at least 0.5v for certain. (maybe the condenser bleeding down?).
This is a problem. When the solenoid is energized, you should get full battery voltage to the distributor wire post. This wire bypasses any resistance wire going to your coil. When cranking your engine, that post should show full battery voltage to GND.
Originally posted by kevin_tbird View Post
Shouldn't the starter solenoid/switch provide battery voltage to the coil?
Yep, FULL voltage.
Originally posted by kevin_tbird View Post
...I'm not seeing a distributor or coil problem, unless the condenser is bad. Can I check that somehow?
Sure! Your condenser is just like any capacitor, but it has a very high voltage rating. Simply put, you can put it in your hand, fill it with a 9-volt battery, and see how long it holds a charge. Use your volt meter. You can also use a resistor in series with the 9-v battery, and see how long it takes to completely fill. If it doesn't hold any charge, it is shorted internally.
Originally posted by kevin_tbird View Post
I HAVE COME TO BELIEVE that I am not getting a signal from the distributor, which I believe means that the points are not closing. I connected an old sears engine analyzer to the dist side of the coil and when the key is turned to run it buried the scale to the right (points open 3.2v+). No amount of bumping the engine along ever moves it off the open. When the key is off it is buried to the left (0v)...
Now we're getting somewhere. Your distributor only DUMPS power to ground. Again, if your ground is missing, it can't complete the circuit. OR, if your points are shorted, the coil can't saturate. Set the distributor cap aside.
Pull your distributor wire off the coil and check the wire to ground while you crank the engine. Use your Ohm scale on 200-ohms (or something low). You should see the points open and close. (You can use a continuity tester for this, too.) If you don't see open-close, fix the distributor wiring.
Using the coil, you can make a spark by pulling the coil wire off and temporarilly replace it with a spark plug wire, with the plug resting on the engine block. Then, ground the D post on your coil. Your spark plug should fire. Moving downstream, ground the open points, your spark plug should fire.
Let's keep talking about grounds...
Is your coil properly grounded?
Is your point set insulated where the wires attach?
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Source: https://www.squarebirds.org/vbulletin/forum/-1958-to-1960-thunderbirds-general-technical-discussion/-1958-to-1960-squarebirds-general-technical-discussion/12330-ignition-and-coil-wiring
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