Theis is an update to accompany the original thread found here:

https://www.ford-trucks.com/forums/1...on-failed.html

I have tried every way from Sunday to hook a GM HEI module into my DSII ignition system (which is currently down due to a fried module). The original thread details all the first experiments and some advice from other board members. This is what else I tried:

The ground was doubled through both bolt holes on the HEI module and run directly to battery ground at the - terminal of the batttery. Again, no spark.

When a voltmeter was hooked to the coil + terminal (where the module had its power) and the coil - terminal, there was 0 V on the display, which indicates that there is no primary voltage on the coil to make it spark in the first place. This is with the wiring instructions done as suggested on various threads throughout the internet. The module was hot, as per the tests written in the original thread.

I then decided to try this on a Dodge slant six truck following the instructions of the slant six forum members who all claim to be happily running these HEI mods on their Chrysler products. The instructions that were followed exactly can be found here:

Slant Six Forum, :: View topic - HEI Electronic Ignition Retrofit How-To

The end result is the same. There is a 0V reading on the voltmeter across the coil primary, even though the voltmeter can be hooked to the coil + terminal and body ground (not ground at the coil -) to show 13 V power at the + terminal. Would somebody please tell me what the missing link is that I am missing here? The coil primary should ground through the module somehow, but hooking these modules up (3 different ones now) never gives juice across the coil primary when I follow the instructions that people have posted. What am I doing wrong?

 

One thing I noticed when I did mine back in the 90s, was that it needed more voltage than what was at the coil +. After the ballast wire got hot, the engine died, and wouldnt re-start until it cooled down. Try wiring the module directly to full (switched) battery power, even if it's just a temporary jumper.

 

There is a 0V reading on the voltmeter across the coil primary

This is normal for a GM 4 pin module.
The 4 pin module does not conduct current flow static without the engine turning round and round.
No current flow means no voltage drop across ANY resistor (coil primary) in the series circuit. Ground the coil NEG to see the voltage drop across the ballast resistor, if you have one in the system.
Jim

 

I don't have a ballast hooked up with the HEI in place. I can't get it to work no matter what. An AC Delco module didn't work either. Also didn't work on a Dodge. I don't get it. I followed all the schematics properly.

 

Go to the web site "go fast for less" and look at the info there. I did my 82 F250 I6 and had no problem. You must bypass the resistor wire from the ignition switch to the coil to provide a full 12 volts. The start wire is non-resister and nothing need to be done. The HEI module must have a good heat sink.

Rod