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Fried hei module??

H

hoover

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Today I decided to try to wire up an hei to a mopar distributor.

When I bench tested it there was awesome spark.

When I tested it on a truck that I'm working, on the terminal that goes to the positive coil arced to the heatsink that the unit is mounted and grounded to. Now there is no spark. I assume that the unit is fried.
I used insulated terminals. Do I need to further insulate it from the the unit from the heatsink?
 
Yeah, probably took out the module. Check that you still have 12v, might be lucky & just blown a fuse....
 
Sounds fried. Definitely will fry it if there was no ground also.
 
I do not believe that is correct. If there is 'no ground', there is no return path from the [+] lead to cause a problem.
 
I had it grounded to the battery, maybe needs a dedicated ground to the engine?
 
No just a ground from the battery should be fine.. I just know from testing them I have blown out a few because of power to it and a bad ground.
 
I picked another hei unit up.
This is my set up. Once it works I will tidy up my wiring.
When I hooked it up and tested it there was really nice spark, but a spark jumped from the coil - to the aluminum plate. Then no spark.

Aside from it not being neat and tidy, do I have something wrong?



20251017_134419.jpg
 
Keep in mind... :rolleyes:
The country of orgin for the HEI module....
Since Delco(USA) stop making these, the majority are coming from the Orient
with questionable quality and reliability....
Try to use an NOS as they are still available, shop around..

Just my $0.02... :thumbsup:
 
Last edited:
Here we go again. If the coil is designed to be used with a bal res, then the bal res should be used with the HEI module.
 
A lot of Chrys Electronic dists have a black wire from the p/up. This goes to the Green lug on the HEI module.
 
HEI modules you have to use a .3 ohm coil Like a GM hEI or a Petronix III No ballast
 
Geoff 2 said:
Here we go again. If the coil is designed to be used with a bal res, then the bal res should be used with the HEI module.
Click to expand...
When i get it to work on the bench I plan to buy the correct coil.
The plan is to hit the scrapyard next week to get ignition parts.
Maybe I'll find some good stuff.
 
Your ground wire that you have. Looks like it runs off module to another mounting point. Does that ground the plate your module is on? And the model is actually mounted to that plate? I ask becuase ground MUST be tight and secure . I always like to have the mounting screws threaded into the plate the module is on.

AC Delco and other modules are not made the same. The eyelets on the AC unit are larger and not a direct ground for the module. Baseplate is responsible for ground.

Screenshot_20251018-085337_Chrome.jpg


This is an LX301 By SMP. Notice the dedicated grounding eyelet and small tab that protrudes off the side

Screenshot_20251018-085535_Chrome.jpg
 
The ground wire from the module uses the same grounding point as the wire that goes directly to the battery, which grounds the plate.
The module is screwed tightly to the plate with the goo that came with it.
 
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