No spark DSII Hei

[WDoug72]

Hey guys, fried my DSII ignition module when I left the key in the run position so I decided to convert to the gm style hei module. Wired everything up correctly and I am now getting no spark. When the key is in the run position there is 12v reaching the duraspark cap. When the key is turned to start, the voltmeter reads anywhere between 7-9 volts at the distributor cap. I brought my ignition module to autozone for them to test it and it checked out ok. All of this and I am still getting no spark. Could leaving the key in the on position fry both my module and coil? Where should I go from here? Coil is reading 8,670 ohms from the negative side of the coil to the center and about 1.7 ohms from positive to negative. Thanks in advance Will

 

[Lazy JW]

..... Coil is reading 8,670 ohms from the negative side of the coil to the center and about 1.7 ohms from positive to negative......l

When I did that it fried both the module and coil.

Just from memory that 8670 ohms seems high but my memory ain't what it used to be. I would try a new coil.
Joe

 

[fordconvert]

12 V at the cap? Nothing on the DS2 should have 12v on it. The HEI / DUI caps have 12v on them because thats where the coil is.

 

[bubba22349]

When the key is in the run position there is 12v reaching the duraspark cap. When the key is turned to start, the voltmeter reads anywhere between 7-9 volts at the distributor cap.

Sounds like you may have the run and start wires crossed! Did you run the white wire to solenoid S term. or start position of sw. and the Red to the run position of ign. sw :

 

[fordconvert]

Either that or dont have the ballast resister in there. Remember the factory DS2 setups still used the resister. I would assume its purpose was same as with points it was being used as a current limiting device which becomes critical in a key on situation if the engine happened to stop turning with the points (or trigger) closed. The GM modules (original ones at least) have a microprocessor in them that does the dwell and current limiting and is smart enough to figure out that the engine is not running and 'turn off'. I dont know if the DS2's had anything but real basic dwell control.

 

[Lazy JW]

The early DS2 ignitions did indeed use a ballast resistor but by the late 70's it had been deleted from the system; these later systems also didn't have the "I" terminal on the starter solenoid as there was no need to send full voltage for starting since they already have full voltage 100% of the time.

With the GM HEI module we do not want ANY sort of ballast resistor/resistor wire in the circuit.
Joe

 

[Stubby]

I thought the ballast resistor was more related to which coil you run.

 

[Lazy JW]

I thought the ballast resistor was more related to which coil you run.

Yes. Through the years Ford actually changed the specs of the coil on the DS2.

 

[80broncoman]

You didn't bolt the GM module to a plastic inner fender or something like that did you??

THe Gm module need to be bolted to a heat sink with heatsink compound and the base of the module must be grounded as well.
Without it being grounded I see it as no spark condition.

 

[WDoug72]

Hey guys, thanks for all the replies. When I installed the DSII system I eliminated the ballast resistor as highlighted in the Classic Inlines tech article "Installing a Duraspark II Distributor". The hei module was installed on a piece of aluminum plate with some heat sink compound. Ill try replacing the coil. Thanks< Will