Shut off while driving will not start

Here are some photos. Did a lot of trouble shooting tonight. The coil, ICM and wiring is a little in disarray since I am tracing wires.

Ask away. I may know the answer off the top of my head.

12.5volts on the positive side.

When I crank the engine and use a light probe on negative side of coil I’m not seeing a flashing light. I can only get a light probe to light up when key is in the off position on the negative side. I feel like the ICM isn’t doing it’s job. Remember it has been nuttered.

Monkeyed with - probably. Lots of electrical tape. I’m gradually peeling it back.

Thanks for the help!

Photos.

Photos for reference.

Medic � thanks for getting back to me and hanging in there!

Sorry for the photos being low quality, it was dark last night when I took them. I am usually working on it at night

Photos attached from this morning showing the connections to the ICM. I have a red and blue going into the module; a green and orange leaving the module (through the factory module female connector) and purple and black leaving the module (through a splice to other wires). When I replaced the module I put everything back in the same configuration as I found them originally. I will re-mount the module to the fender wall (where I found it) tonight � had it out to help with diagnosis access. I am a little concerned about all of the splices, though they were there when I got it.

A couple of other points ("light" refers to probe test light lighting up)

Coil:
- It has a "TFI upgrade" per PO which uses a coil from a 90’ Ford. The coil has a bracket that will mount it to the fender that I will re-install.
- I was getting zero resistance from positive to negative on the old coil (after I had replaced the alternator) so I replaced the coil.
- New coil - I get a +/- 0.5 ohm reading from positive to negative.
- New coil � I get a +/- 7500 ohm reading from positive or negative to distributor lead.
- Got a "light" when I probe the positive (Red) wire connector at the coil when the key is in “on” position.
- Got a "light" when I probe the positive wire connector at the coil when I crank the engine.
- NO "light" when I probe the negative (Green) wire connector at the coil when the key is in “on” position.
- Got a "light" when I probe the negative (Green) wire connector at the coil when the key is in “off” position.
- NO "flashing light" when I probe the negative (Green) wire connector at the coil when I crank the engine.

Module:
- Replaced the module (after I replaced the alternator) as I was told that could go with the alternator by the P.O.
- I get a "light" when I probe the blue wire going to module (harness side) when I crank the engine. (2-wire connector)
- I get a "light" when I probe the larger red wire going to the module (harness side) when key is in "on" position. (2-wire connector)
- I get a "light" when I probe the black wire (Ground) at the connector (harness side) to the module (4-wire connector)
- I made a jumper wire from the battery negative to the coil negative (Green) and got a "light" when I tested the green wire at the connector (harness side) to the module (4-wire connector)

Distributor:
- I get a "light" when I probe the black wire at the connector attached to the distributor. Seems to confirm the distributer is grounded.
- I put a spark plug test light in one plug wire and get no light when cranking.

Starting Solenoid:
- Replaced it (after I replaced the alternator).

Other thoughts:
- Battery holds charge at +/- 12.6 V
- When the alternator died, could that have "taken" anything else with it?
- Could I have caused another issue when installing the new alternator?
- Could having the module not mounted to the fender cause the problem?
- Could having the coil not mounted to the fender cause the problem?
- I am not sure I have confirmed the orange and purple wires from the module to the distributor are not broken.

Hope all of this is clear (as mud) enough to make sense on your end. Let me know what thoughts you have!

Photos above - 3 from this morning of the module and connections, 3 from when I bought it showing the original state of everything - pre alternator and ignition issue.

Yes I do. You list the tests and I’ll report back with numbers and my findings. Thanks!

Was hoping to find something obviously wrong but didn’t! Uggh.

Battery voltage = 12.58
Voltage at coil positive with key “on” = 12.36

Showing 0.2 ohm when testing distributor ground black wire per your photo.

Showing 619k ohm when testing orange and purple at distributor per your photo.

Traced orange, purple, black, green from coil and distributor and they land where they should per your photo. I also checked continuity from end to end and got 0.1 ohm from end to end.

That would be a bad joke! See photos of distributor. Confirmed it is turning when spinning. Checked for spark with tester and didn’t get one.

Re mounted the coil and ICM.

Thoughts? Thanks for the help.

Alright! Battery has been on a charger so it’s a bit higher than normal. Just now the battery voltage is 13.11 and the red wire is 12.91 with key on. Other wire has no voltage with key on and 11 volts when cranking.

No I haven’t picked up the distributor since it last ran, just opened the lid a couple times. I have tried to turn the rotor by hand and cannot without too much force. I’ll check for spark the old fashioned way tomorrow and report back. One note, when I purchased the module I didn’t ask them to check it. Think it could be defective? Also should I get any specific readings on the green wire leaving the coil when I am cranking the engine?

Update: I removed some old splices and connectors at the ICM and reconnected it. Was able to get a spark on a test plug per your photo. Replaced the plug wire and she fired up. Kept foot on gas for a bit and let her run for one minute, sounded normal. Tried to slow to idle and she stalled out. Went back an hour or so later and she started up again and sounded normal. Then stalled when I pulled the headlight plug to see if they worked when engine was running, stalled out. Now I cannot get a spark again. Back to where I was.

Now, with key on, reading battery voltage at the red ICM wire, at the + and - coil wire and red wire at starting solenoid. With key off I’m seeing battery voltage at - green wire at coil. Getting 0.5 ohm resistance on coil + to - and 845 k Ohms from + to distributor wire.

I’m using a MasterCraft ICM.

Help! I am out of ideas. What am I missing? Everything seems to be reading per your pictures and diagrams.

Thanks. Frustrated in Texas!

I just needed a pep talk! Thanks for hanging in there and getting back to me. I bet it’s hard to text out solutions to problems sight unseen. Really want to figure this out!

Key off - no power on positive at coil, but I do have battery voltage power at the negative side (one tester lead on positive battery terminal, one on green negative connector).

Connector to module 2-wire side - power at red only when key on. Both have power when cranking. No power to blue (white in your photo) when key is on.

No ballast resistor to be found. Been looking for one but haven’t found it. Should there be one?

Keep the ideas coming!

Volt meter negative lead on battery negative. Key off. Positive lead on negative connector at coil. No read. Key on. Reads 12.67 volts. Battery voltage is 12.76 volts.

I have a jumper wire from what I can tell that follows the path of your photo. It splices in at the red wire through the firewall by driver, runs over top of engine to near the coil, splits and feeds both the coil and the starting solenoid.

No ballast resister. Should I have one cut in the jumper wire?

Alternator has a two prong connector with one wire leaving it that is brown. There is no ground wire hooked to the alternator.