OK We did this on a 83 D150 with slant six 225 ci. last year. Ran great for about a year. Backed up a small hill....heard a pop noise and truck stalled. Now wont restart. Replaced the coil, ICM, Relay, and the dizzy (all new). Already has new plugs, wires, cap and rotor.
Still no spark. Thanks for any help

I don't know of any specific troubleshooting tips. Back in the day, the GM guys would usually carry a spare module and rotor (for coil in cap applications). You can measure the resistance of the distributor pickup, I forget the resistance range, but you are basically looking for an open circuit. Coils can go bad, but they are basically simple devices and not really prone to failure. The modules were the weakest link back in the day. Even more so these days because of the poor quality of replacement parts available.

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-MattMan
LEANED & MEAN

Not trying to be dumb but is the rotor spinning? And you do have power to the coil and HEI module ?

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

Yes rotor is spinning. !2 volts to coil and ICM. However I have noticed the wires from ICM to the dizzy show 3.5 volts and I am not sure why.

When i test across the dizzy wires i get a reading of 234 - 265 ohm on both dizzy???

it seems as if i am not getting a signal from the dizzy (either one). Very odd.

You can't properly test the distributor pickup with a volt meter. The resistance you measured seems ok. My bet is still the module.
jus sayin....

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-MattMan
LEANED & MEAN

Had the shop double check new and old ICM .. New one good old one bad. Will get back to it on Sunday.

D

I meant that you can't really check it with VOLT meter, but you can with an OHM meter.
Sorry for the mis-understanding.

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-MattMan
LEANED & MEAN

Actually, you can do a test with a volt meter as well. The pickup generates an AC voltage as reluctor teeth pass the pickup. You can see this on an volt meter pretty easily when set to AC. Turning the distributor faster increases the voltage output.

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Joshua

Good to know. What is a good AC reading?

_________________
2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

Ok We went over every connection again, new coil, ICM, Dizzy. It started right up quickly and ran at high idle for a couple minutes. I had to shut it down as we were not expecting it to start and had left the dizz hold down clamp off. Turned key off and it shut down. Took the battery charger off (it was only on a 2 amp setting). Installed the hold down and went to restart. Cranking not starting. Checked and have no spark again.
1) Noticed I get a single spark when I first try to start (first bump). We are using a remote starter switch right off the starter.
2) Noticed in the past when I would turn the key off I could feel the motor rotate ....not a lot but I could see the fan blade move 1/2 inch or so.
3) Also have now noticed the seat belt warning light/buzzer will come on sometimes and not other times.
Starting to think maybe a ignition switch problem. I think we could bypass the inside switch and use remote switch to test the idea. Of note when it started I was using the remote switch. Huuuuuummmmm

update Well i am at a loss. We got it running again by "PULLING UP ON THE DIZZY" just a 1/8 to 1/4 inch or so. When it is fully seated on the block pad it will not start. WTH???? Is there a bushing or something that spaces this dizz up ???

Pull the distributor out and look at the bottom gear. How much play, up and down, does it have. Something is wonky here! Double check everything inside the distributor. If the only thing that makes it start is the distributor being pulled up a little then something is wrong with the distributor somewhere. Good luck.

_________________
2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6