Duraspark II/HEI conversion failed
The schematic I used is as follows:

Module pin details:
B = HEI module power in and coil + terminal power in
C = HEI module to coil - and tach
W = HEI module to DSII stator orange
G = HEI module to DSII stator green
I wired everything up with the proper terminals using this exact arrangement except my B terminal connection does not feed off of the coil + terminal as a bus location. Rather, my ignition switch feeds both the module and the coil + from a T-junction right outside the firewall (shouldn't matter, my duraspark was like that too and lots of chrysler boys do it that way).
Specific parts used in the experiments:
14 gauge primary wires of different colors
crimp connectors: 1/4" female on pins B, C, and W and 3/16" female on G
Cardone reman DSII distributor that was put on the truck over a year ago for a 1981 F100.
bread loaf pan was drilled such that the 8/32 screws used for the module actually screwed in. This was to be my makeshift heat sink, because it is dreadfully difficult to find a spot to mount the HEI on my 86 F150, and porper heat sinks were not to be found in BFE where I live. Lack of resources and creativity are close cousins.These were the initial pieces I selected to run the experiements, with the idea that I would get a better heat sink and pay shipping costs for one if it was worth my time.
The experiments:
The module was mounted to the bread pan which was in turn bolted to the plastic inner fender well just between the DSII module and the wash/radiator overflow bottle. The wiring was set up as per the diagram above with only the mentioned T-junction arrangement of the supply voltage circuit as a midification. Everything looked neat and proper, so the key was turned. A no-fire condition was confirmed by a spark tester following several disappointing attempts to fire the engine. A voltmeter was hooked to the supply voltage circuit to determine potential vs. key position, just to be sure (I already knew this was fine due to the duraspark conversion I did from EEC-IV the previous year, but better safe than sorry). I also did other critical voltmeter tests.
Key position test:
Run position = 12.6V @ module B + and 12.6V @ coil +
Start position = exactly the same as run
The basic primary voltage was fine and active in both critical key positions.
Module power and ground:
The negative voltmeter lead was touched to the screw where the black wire to the distributor base was connected, and the positive lead to the module B+. 12.6V
The module was powered up and grounded.
Module power and ground rework:
direct battery terminal + and - connections were run to the module with test wires and gator clips. The coil + was also included. Cranked it and no spark.
Duraspark II module test run: To inspect the integrity of the orange and purple stator connections, the original DSII module was hooked up with the exact same wires that were in place on the HEI module. The 4-pin DSII module plug recieved the wiring from HEI in this specific fashion:
HEI C terminal to coil - was hooked to DSII green lead
HEI B terminal to coil + was hooked to DSII white power in
HEI W orange lead was conncted to DSII orange stator lead
HEI G purple lead was connected to DSII purple lead
HEI distributor ground was hooked to DSII black lead with a gator clip
Key was turned and the engine fired up and ran perfectly within 1/2 second.
HEI double ground: a whole was drilled in the cake pan which tested 0.00 ohms in a continuity test to determine conductivity. The whole was connected by a lead to the battery negative terminal to provide ground connectivity across the entire back of the HEI module (assuming that the heat sink compound is conductive. Again no spark.
HEI module replacement: The module was taken back to Advance and swapped for a new one. Again, no spark.
Conclusion: The BWD HEI module cannot communicate with the cardone reman stator to complete the ignition firing circuit.
Does anyone know what the hell is going on here? Have I missed something? Any input will be appreciated.
I hooked the DSII back up, because the truck is my daily driver, and I cannot be without it. It still does not have the ballst resistor. The coil I am using is this:
This coil is available for all the later model TFI and EFI Ford motors that didn't use ballasts, and the input voltage is rated for 12 V. To me that means that the ballast is not necessary, because the coil has its own built in resistance. The DSII module runs a constant 12 V anyway, so I figure I might just say the hell with the HEI mod as long as this coil is going to survive a no-ballst condition. There are tons of confliciting reoprts on the internet in regard to whether or not coils and modules for DSII live through the no-ballast scenario, but it seems to me that if the coil has its own internal resistance built in, then there is no need to worry since firing power is going to be normalized to the same thing. That being said, what thoughts do we have out there regarding this topoc in general? Is it even worth it to bother with the HEI since it didn't work for me, and the DSII is a fine ignition anyway? Thanks folks.
B = HEI module power in and coil + terminal power in
C = HEI module to coil - and tach
W = HEI module to DSII stator orange
G = HEI module to DSII stator purple
that should say purple on pin G above
The ballast resistor will drop the current flow in half. The street fire coil most likely will have about half the primary resistance as an old round coil, which will double the current flow.
So your current flow is about 4 times the stock IGN system DS2 module was meant to handle. Thus a HOT DS2 module.
The only ideas I have on getting the 4 pin module to work is be sure and add an extra ground on the mounting screw the has the metal inside it. It is on the left in your photo.
Also try swapping the to stator wires on the 4 pin module to see if it helps.
To get the DS2 module back on line you will ballast resistor to lower current flow to the DS2 module. An old round coil would also help as it has a higher primary resistance, 1.2 ohm,
The ballast resistor should be close to equal the coil primary resistance, to divide the supply voltage equally, 6v and 6 volt.
A 1.2 ohm ballast with a .6 ohm coil PRI will only leave 1/3 of the supply voltage to the coil positive. Say 8 Volts and 4 volts split. It might not run with 4 volts supplying the coil.
Jim
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The photo was taken at first intall/testing. I had consider the ground wire extra and really not needed as it was well grounded to the metal engine attachment. I disconnected the knife connector at idle and the engine quit.
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There has to be some untold disparity between the BWD module and the cardone reman stator. Everything else is hot and ready to pour the coals.
Anyway, I am frustrated to death now. I went and bought another ballast resistor and DSII module. I'm just going to hook the stock ignition back up. HEI is not working on my truck, and I have no idea why. I did everything to spec and followed all the advice so far. Unless I got two bum HEI modules in a row (unlikely), the cardone reman stator and the BWD HEI module simply do not communicate.








