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'75 2002, stock ignition system (no ad-ons).  Only deviation from stock is a Bosch blue coil.  


What's been checked:

  • points, plugs, cap, rotor, condenser and plug wires are new
  • Point gap is correct at .016
  • coil was tested for resistance and is within specs
  • +12 volts at the coil's low tension terminal
  • tried a second Bosch (black) coil; no change



  • no spark at all, using a new spark plug connected to #1 plug wire and resting on the valve cover



  • Should I be using the OEM resistance wire to power the coil or is that diminishing the voltage at the (blue) coil since it has built-in resistance?  And if that's the case, where do I bypass the resistance wire (i.e. where does it start so I can cut into the harness and replace it with a regular wire)
  • There's a bundle of three wires inside a blue sheath.  I know the two black wires go on the negative coil (#1) terminal--one to the distributor, the other to the tach, and the third clear insulated resistance wire goes to the positive coil terminal (#15).  Where does the other black wire go?  It's by itself in a second, smaller blue sheath and AFAIK was connected to the positive #15 terminal.


Help!  Trying to have a running car in time for this weekend's Spring Drive in northern KY.



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Pull the centre HT lead off the distributor, hold the rubber part and direct the metal end close to a metal engine part: do you get a spark then you disconnect either low tension wire from the coil (ignition on)?  If yes, coil & wiring good, if no then coil or wiring bad.

If yes, then take a look in the distributor: are points opening& closing as engine cranks? Is the rotor arm in good condition? Try changing condensor.


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With the Bosch blue 3 ohm resistance coil you don't want the original resistor wire. The resistor wire goes about 3 ft into the harness, around middle of the firewall. It feeds from the #4 fuse but isn't fused.


The only other wire than the green power wire on the positive  15 terminal should be a black/red wire going to the starter for voltage boost while cranking.


I would also suggest trying another condenser, I've had a few duds brand new.


Check your ground connections too.

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