Coil changed coil still no fire from coil but harness wires are hot.

You need to test the output of the wiring harness. Sometimes the wires degrade and you won’t get spark. Best thing to do is crinkle the wires around with your hand while it’s running and see if it changes the idol. If it does that’s your problem.

consider substituting the ECM and checking all of the electronic harness connections

Since the problem remained in the same position after a coil swap, your next step would be remove the ignition module below the coils and have it tested at your local auto parts store. Also inspect the wiring harness and plug going to the ignition module for a bad connection.

https://s21.postimg.org/wwpncpluf/pcm_power_relay.jpg

Click on the link.
Voltage for fuse 18 comes from, pcm power relay.
Terminal 30, load side of relay is fuse protected and hot all the time. If you unplug that relay and use jumper wire between terminal 30 and 87, fuse 18 should go hot. That should mean, the control side of relay has a problem, The control side needs voltage and ground.

asd relay or fuse
camshaft not spinning
bad pcm
damaged wiring harness

Hello! There is a wiring multiple between the four coils of the Red and Black (+12 and Ground) wiring that may have opened up during the head replacement...On Coil #1...Pin #3 is a Red wire and on Pin #2 is a Black wire...It is the same on Coil #2...Using two safety pins...Push the points into the Red and Black wires...First on coil #! then #2...Set your meter to read 12 volts...Clip the (+) meter probe to the safety pin in the Red wire and (-) to the Black...Turn on the key...12 volts must be present...You can check the other two coils that are firing...More than likely those two will read OK...This is a preliminary test to insure #1 & #2 have the proper voltage...Send a comment with results and I'll take it from there...Guru...Saailer

I’m happy to help further over the phone at https://www.6ya.com/expert/david_6df67de3b14de867

If it got that hot you may have to replace the wiring harness.....sorry. Not to mention you could have cracked the head !!

'56 engine was likely a "blue flame" engine that had a points type ignition system. If someone installed a HEI setup in there, you need to know what year vehicle it came from. The old system used a hot wire from the ignition switch to the (+) side of an external coil...the (-) lead went to the points. The most common conversion uses the same (+) wire but it then connects to the "batt" terminal on the distributor cap.(coil is inside) There are no other wires involved except for the short harness that goes directly into the distributor that connects the coil, pickup coil and control module to each other..

yep! sounds like you have an broken wire in harness

If the spark for the coil is not hot hot enough it wont fire plugs... I assume you have checked wires