Electronic Distributor conversion no spark

[usraptr]

70 Cuda 440, 4 speed, Rallye  Dash.  New engine build. Car wasn't running when I bought it.  Using original wiring harness which is in good condition.  Clutch is depressed. Trying to convert to an electronic distributor with no success. Purchased the Summit electronic distributor and ECU, etc.  From what I can tell it's pretty much a copy of the Mopar kit.   Blue wire from ECU is hooked up to the "Run" wire (blue wire J2-16DBL)) coming from the bulkhead connector No. 23.   Black wire from the ECU is connected to the Neg side of the coil.  Green wire from ECU is cut off.  I have 12 volts going from the "Run" wire entering the Ballast Resistor and flowing to the opposite side post (new 2 post resistor that came with the kit).  The J3-14BR/T and J2A-16DBL are connected to the opposite side of the resistor.  The J3-14BR/T goes to the bulkhead connector No. 22.  The J2A-16DBL goes to the positive side of the coil.  However, when I connect J3 and J2A to the resistor and then check the voltage at the positive side of the coil I only have 4 volts??  Battery is new and fully charged.  Engine turns over but I'm not getting any spark to the distributor.  I checked the Ohm resistance in both the ballast resistor and the coil and they are within specs. 

Side question, if everything is hooked up correctly and the key on, am I supposed to get a spark between the reluctor and stator when I rotate the distributor by hand (setting static timing) with the key on and distributor cap off like you do with an old points type ignition?

[Chryco Psycho]

ok sounds like the wiring is correct except the brown start wire needs to go to the coil side of the ballast so it will get 13.2v while cranking
 you should never have a spark between the reluctor & pick up coil but rotating the dist should create a spark from the coil .

[dodj]

 
The start (brown) wire needs to be on the opposite side of the resistor from the run (blue) wire.

[usraptr]

Ok, sorry I just realized I used the wrong designation for the Blue wire connected to the J3-BR wire.   So two clarify the J2-DBL wire is the "RUN" wire coming from Bulkhead position No. 23.  The J3-BR and J2B-DBL are connected together and attach to the coil side of the ballast resistor.  The J3-BR wire goes to position No. 22 on the bulkhead and the J2B-DBL goes to the positive side of the coil.  With the  key in the "run" position I'm only getting 4 volts to the positive side of the coil  through the J2B-DBL wire.  Is that going to increase to 13.2V when I turn the key to the start position?

[734406pk]

Ok, sorry I just realized I used the wrong designation for the Blue wire connected to the J3-BR wire.   So two clarify the J2-DBL wire is the "RUN" wire coming from Bulkhead position No. 23.  The J3-BR and J2B-DBL are connected together and attach to the coil side of the ballast resistor.  The J3-BR wire goes to position No. 22 on the bulkhead and the J2B-DBL goes to the positive side of the coil.  With the  key in the "run" position I'm only getting 4 volts to the positive side of the coil  through the J2B-DBL wire.  Is that going to increase to 13.2V when I turn the key to the start position?

You ignition wiring should look like this:

[734406pk]

With the key switch in the "run" position, you should have full battery voltage between the Blue wire and ground. With the key switch in the "start" position, you should have battery voltage between the Brown wire and ground. The brown wire bypasses the ballast resistor while cranking. Be sure to have the ignition ECU module well grounded. Installing a ground strap between one of the ECU mounting bolts and a bell housing bolt is one method.

[usraptr]

734406pk, thanks for the diagram.  That is how my system is wired. I'll try the ground strap and report back. 

[1 Wild R/T]

The thing that concerns me is this is a fresh engine, don't keep cranking the engine over or you'll wipe the camshaft....  Personally I'd pull the distributor & just spin the distributor shaft to get spark... Besides with the distributor pulled it's real easy to check the reluctor to pickup gap which should be .008-.012 & honestly I try to get closer to .008...

[734406pk]

" However, when I connect J3 and J2A to the resistor and then check the voltage at the positive side of the coil I only have 4 volts?? "


 This reading is correct. The voltage drop is caused by the ballast resistor doing it's job. The longer the key switch is left on, the ballast resistor gets hotter and more resistive (up to a point). With the key on/engine off, check for battery voltage at the blue wire on the ballast resistor. Then disconnect the starter relay (to keep the starter off) and turn the key switch to the start position, check for battery voltage on the Brown wire on the ballast/ coil positive terminal.

[usraptr]

IT'S ALIVE!!  Found the culprit.  It was the Gray Tach' wire that was hooked to the negative side of the coil as per the service manual.  On a hunch I disconnected it from the coil and the egnine fired right up.  Scared the crap out of me after all the false tries, especially with wide open headers.  Immediately shut it down.  My son is coming over after work and we'll do the 30 minute cam break in at 2500 RPM. 

Question, if the tach wire doesn't go to the negative side of the coil as per the service manual where do I connect it so my Rallye Tach will work?

" However, when I connect J3 and J2A to the resistor and then check the voltage at the positive side of the coil I only have 4 volts?? "


 This reading is correct. The voltage drop is caused by the ballast resistor doing it's job. The longer the key switch is left on, the ballast resistor gets hotter and more resistive (up to a point). With the key on/engine off, check for battery voltage at the blue wire on the ballast resistor. Then disconnect the starter relay (to keep the starter off) and turn the key switch to the start position, check for battery voltage on the Brown wire on the ballast/ coil positive terminal.

I checked the voltage at the blue wire and it was 12 volts.  In the start position the voltage at the BRN wire jumped from 4 to 12+ volts.

The thing that concerns me is this is a fresh engine, don't keep cranking the engine over or you'll wipe the camshaft....  Personally I'd pull the distributor & just spin the distributor shaft to get spark... Besides with the distributor pulled it's real easy to check the reluctor to pickup gap which should be .008-.012 & honestly I try to get closer to .008...

I hear your concern, but I didn't crank it that much so hopefully I'm okay.  I primed the oil pump/engine several times (including yesterday) before cranking and finally firing the engine and I immediately shut it down when it started.  Plus I had Joe Gibbs break in oil with high zinc content and a bottle of Edelbrock cam break in oil mixed in with it.

Thanks everybody for the suggestions, diagrams and advice.  It's very much appreciated.  You guys rock!     The people on this forum are assume. I don't know how people did this stuff before the Internet!
I'll do a video of the start up and break in tonight and post it on my Restoration Page!

[734406pk]

The tach may be shorted to ground somewhere?? The voltage readings you have are correct. Congrats on finding the issue! Now for the break in, have a water hose ready to mist the radiator, a new engine will generate a ton of heat! Best of luck!!

[usraptr]

Thanks 734406pk.  As much as I was looking forward to doing the break in tonight, I have a leaky fuel pump connection that I wasn't able to resolve today due to having company come by the house.  Hopefully I'll get it resolved tomorrow and we will do the break in tomorrow night after my son gets home from work.  Roger on the hose.  Good idea.

[734406pk]

YES- Take care of that fuel leak first!! Perform the break in when you have time, no need to rush it. Post a video if possible. 
Nice Avatar BTW LOL!!

[usraptr]

YES- Take care of that fuel leak first!! Perform the break in when you have time, no need to rush it. Post a video if possible. 
Nice Avatar BTW LOL!!

Fuel leak fixed.  Video camera ready.  Just waiting for my son to come over after work.  Rat Fink rules!!

[734406pk]

Good luck with your break in!!