We changed the coil, points, condensor, plugs, wires, battery, and no spark??? What am I missing? Plus, we bought a new carbeurator. Any ideas?
Is there 6 volts at the coil, or 12 volts when the starter is turning? Are the points gapped properly? Is the points dwell angle set right? The coil is easy to check to see if it is good. Compare the impedance on the primary and secondary coils. Is the coil producing spark, but it is not getting the the plugs? Check the distributor cap and rotor for cracks. Cracks let the spark ground before going through the wires.
THanks for replying. I’m only getting .2 volts at the coil. I replaced the coil but my other one was too rusted. So I’m not sure which wires go where. Black is on negative and red is on the positive post of the coil.
Did you clean the point contacts? The points are often coated with shellac to prevent corrosion. A shot of brake cleaner on the contacts will usually bring them to life.
Also, could a faulty regulator cause this?
Hi Rod Knox. Yes new points were cleaned.
Did you check the ballast resistor or wire coming off the distributor (or coil?). Went through the same thing with a 71 Buick many years ago. It’s easy to overlook.
Ed B.
Hi Ed, yes that’s the black wire on the negative side of the coil. Is this the right place it should be?
Only getting .2 volts at the coil may be a bad ballast resistor or bad wiring.
Thank you BustedKnuckles. I will be sure to check the ballast resistor and wiring.
I guess I didn’t know about the ballast resistor. What is it and where is it located?
There is no ballast resistor in this ignition system. Fords of this vintage use an ignition primary resistor wire. This wire runs from the ignition switch to the + side of the ignition coil. If you’re only seeing .2 VDC at the ignition coil, then there could be a problem with the ignition switch or the resistor wire.
Tester
Thank you Tester. This is very helpful. Can I jumper from positive post on battery to positive post on coil in order to bypass the starter (faulty wiring)?
0.2 volts at the coil could mean that the points are simply closed when you took the reading. Put the negative lead of your meter directly on the negative post of the battery. With the meter’s positive lead measuring the DISTRIBUTOR side of the coil slowly turn the engine by hand, turning the fan if possible or crankshaft if necessary. When the points are OPEN you should read 12 volts. When the points close you should read very close to 0 volts.
If your readings vary from this, that’s your problem. Find out why.
Yes, you can jump everything and put a wire directly from the battery positive to the coil’s positive, but don’t leave it there any longer than it takes to verify that you do or do not have spark. The increased voltage will burn the points.
Thanks Jay. We have been thinking about this too.
Okay Jay. Good to know on jumping.
When the points are closed…Pull the coil wire off the distrib cap and have it near a ground source…if you open the points with a paint stirrer or Bamboo Skewer…you will hear or generate spark at the coil…it is a quick and EZ test to do while you are troubleshooting this issue…to see if you finally got it… Just keep flicking the points open to see if you affected a “shocking” change…prevents you from cranking it over not knowing if you have a spark yet…
Blackbird
New points should be filed or they may not work. Once they’re roughed up they make good contact. It doesn’t take much.
Yup Rod Knox hit on that issue…his Brake cleaner idea will take care O that
Thank you so much everyone. All of you have been most helpful. 