Hey guys. I have a Chrysler 251 Flathead 6 that was converted to a 12 volt system a while back and now all of a sudden I don't have spark. Admittedly, I don't consider myself an electric system wizard by any means, but I've been fooling and testing now for a week and I just don't understand what my problem is. Any help would be appreciated. I do have 12 volts to the coil when the ignition on, so I think eliminates a lot of other things that could be wrong. The coil is fine because I swapped that out with another one I know is working and I still didn't get any spark. Sorry purists, but I not only converted to a 12 volt system, I put a Pertronix in it also. That seems to be OK because I think it is grounded fine, but not sure how to test that, as their website is helpful but doesn't have any tests that I can see. Does anyone have any tests that I can do to start eliminate things? If you have any questions for me to help out, please let me know and I'll do my best to answer with my limited knowledge.
I can try this tomorrow night: Do you really think it's the Pertronix? Remove the distributor cap without removing the plug wires to gain access to the PeTronix parts. Connect one end of a 36-inch jumper wire to the battery negative terminal. Connect the other end of the jumper wire to the Ignitor module base plate. Inspect the Ignitor wiring connections and look for damage. Pay particular attention to the ground wire inside the distributor for proper connection. Repair or replace any improperly connected or damaged wires. Unplug the red Ignitor module wire. Connect the red Ignitor module lead to the battery positive terminal using a jumper wire if required. Attach the black lead of the multimeter to the Ignitor module black wire. Attach the red lead of the multimeter to the battery positive terminal. Rotate the center magnetic sleeve of the distributor shaft by hand or by cranking the engine. The multimeter should show a fluctuation between battery voltage and zero volts. A constant voltage reading indicates a failed module or improperly installed Hall Effect shutter wheel. Measure the clearance between the center magnetic sleeve and the Hall Effect shutter wheel using a .030-inch brass feeler gauge. If the clearance is greater than .030 inches, the shutter wheel must be adjusted. Loosen the shutter wheel mount using a flat-head screwdriver and reposition the wheel to a .030-inch air gap. Tighten the hold down screws and double check the clearance. Repeat Step Three after adjustments have been made. Disconnect and remove the digital multimeter. Disconnect and remove all jumper wires. Connect the Ignitor leads in their original locations. Install the distributor cap and fasten it down securely.
When I test ohms from the base of the pertronix to the neg battery terminal I have 1.6 ohms which is way higher than the .2 recommended. But I don't understand what that is telling me. I can find a ground easily with .2 ohms. Am I supposed to run the pertronix black wire to that instead of the neg side of the coil? How is the coil grounded anyway? I tried running a jumper from my good ground to the neg side of the coil and my resistance ballast started to heat up. I'm lost!
Did it ever work after you converted it? If so, that would eliminate wiring and point to the petronix, if not...look deeper into the wiring.
Yes it worked fine up to about 2 weeks ago when I disconnected the kill switch. I guess I took for granted that it was a simple two wire connection vs. disconnection kill switch and didn't keep track of the wires when I disconnected the kill switch. I think I have all the wires in the right place, but might have fried something in the process. Maybe I don't have the right wires in the correct places. I attached a diagram of the way the wires are connected. Please feel free to let me know if I have this wired incorrectly. I may have grabbed the wrong wires when I disconnected the kill switch. I'm afraid I got in too deep here for my own knowledge.
In your diagram, is that a ballast resistor under the starter and above the fuel pump? Anyway, can you post a copy of your petronix instructions?
Yes that is a ballast resister. I don't have an evident part number on the pertronix, but the install is all about the same. http://www.pertronix.com/docs/instruction-sheets/1164.pdf Worked all summer just fine.
I took the coil wire out of the disty and stuck a spark plug in it, grounded the plug, and I didn't get any spark. The coil wire tests OK and the ohms from my coil tests OK. I have 12 V at the coil when the key is on and it drops to 10 V when I crank the engine. That is to be expected, correct? Do you guys have any idea what this could be?
Connect your voltmeter + to the coil -, voltmeter - to ground. With the ignition on, is 12v at coil -? If so, spin the engine and see if the voltage falls below about 5 volts. If it doesn't fluctuate, your pertronix module has a problem. Digital voltmeters are state of the art, but an old Simpson 260, with its analog dial can save a bunch of time here. Sent from my SAMSUNG-SM-G930A using The H.A.M.B. mobile app
Pull a plug and ground the strap to the block while cranking the motor. You will either see it spark or not. No would indicate a problem with the Pertronix. Put the points back in.
When I connect a test light to the - side of the coil and crank the engine the light does not flash it is a steady light. I also removed the wire from the - side of the coil and I have power at both the + and - sides of the coil when the key is on. This should tell me that the coil is fine and that the problem is with the pertronix or the wire from the coil - to the disty.
Why would it blink when cranking the motor? The disty should take care of the 12 volts on and off. That's with the points or pertronix is for, correct? I just performed a negative ground module test that is on the pertronix website and I believe it failed that test. I will try to upload a short video of it.
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