(Problem Solved!!) Need help: car has been running fine but now no spark

[Road_Runner]

I pulled a plug and turned the motor over with a remote starter and the ignition on.  NADA, no spark.  The plug was wet so its getting gas OK.  Swapped out the coil, resister and ignition box with a new orange one I had but still nothing.  When I swapped coils I was sure I found the problem when the negative lead fell apart.  Fixed that and still nothing.  I went ahead and ordered a new engine harness but any ideas what I can try in the meantime?  Not very skilled troubleshooting electrical issues but something tells me I better learn!

Thanks in.advance, Jim

[Jamiez]

Neutral Safety Switch (auto) or Clutch Safety Switch (manual)?

Both of those will prevent the car from starting.  You can bypass them for testing.

[Road_Runner]

Neutral Safety Switch (auto) or Clutch Safety Switch (manual)?

Both of those will prevent the car from starting.  You can bypass them for testing.

Would that still allow the starter to spin?  I should have added that it turns over fine, just no spark at the plugs.

 Thanks, Jim

[Bullitt-]

Are you getting full power(12V) to the ballast resistor with the ignition in the start or on position?  If not suspect connections at the bulkhead, steering column or possibly a bad ignition switch.
Several folks have found the reluctor in the distributor to be out of adjustment or bad.

[Road_Runner]

Are you getting full power(12V) to the ballast resistor with the ignition in the start or on position?  If not suspect connections at the bulkhead, steering column or possibly a bad ignition switch.
Several folks have found the reluctor in the distributor to be out of adjustment or bad.

Back when I worked on these cars as a kid the electrical systems were new and not the rotted mess they are now!  So I have very little experience troubleshooting electrical problems.  Do I just disconnect the connector at the ballast and put the probe from the multimeter in, and if so does it matter which slot?  I wondered about the distributor as its probably original like a lot of the car, wore out but original.  The dash wiring is a mess, too.  Lots of previous splices, etc.  So everything is suspect, and all suggestions are greatly appreciated.

Thanks, Jim

[dodj]

I like bullitt's suggestions. Especially the reluctor gap. Set to .008 i believe with non magnetic feeler gauge.
Single or dual resistor?
By the way, has this motor run recently?

[Jamiez]

Would that still allow the starter to spin?  I should have added that it turns over fine, just no spark at the plugs.

 Thanks, Jim

No if those were bad the car wouldn't crank at all as they are designed to prevent you from starting the car in gear.

[Bullitt-]

You don't even need to disconnect anything if you can get your meter probe to contact the connector (on my 73 this would be easy, just slip the probe inside the insulator)
Set your meter to DC on the lowest setting above 12V. Find an earth ground for the black probe & contact the red probe with the brown wire at the ballast resistor, turn ignition to on position & check meter. Turn ignition to start, check meter. Both should register about 12V.

This link shows checking reluctor gap .008 http://jtsjunkyard.blogspot.com/2011/04/rebuilding-chrysler-electronic.html
Did you look at your rotor button? They can just break 

[Road_Runner]

You don't even need to disconnect anything if you can get your meter probe to contact the connector (on my 73 this would be easy, just slip the probe inside the insulator)
Set your meter to DC on the lowest setting above 12V. Find an earth ground for the black probe & contact the red probe with the brown wire at the ballast resistor, turn ignition to on position & check meter. Turn ignition to start, check meter. Both should register about 12V.

This link shows checking reluctor gap .008 http://jtsjunkyard.blogspot.com/2011/04/rebuilding-chrysler-electronic.html
Did you look at your rotor button? They can just break 

Excellent instructions even I can follow!  I'll have to get a non conductive feeler gauge as mine are metal, but I'll check this probably Thursday when I'm back in town and report back here.

Thanks again, Jim

[Road_Runner]

I like bullitt's suggestions. Especially the reluctor gap. Set to .008 i believe with non magnetic feeler gauge.
Single or dual resistor?
By the way, has this motor run recently?

Dual resister, and the car has been starting fine before this.  I had an issue a year or so ago where it was stalling unexpectedly and usually at the worst times (sideways in an intersection, etc.) but after replacing almost all the electric components under the hood that cleared up.  So this is a new symptom at least, and possibly unrelated to the earlier issues.

Thanks, Jim

[RzeroB]

Excellent instructions even I can follow!  I'll have to get a non conductive feeler gauge as mine are metal

They can be metal, they just can't be magnetic (steel). I have brass feeler gauge set for the job

Also, check out this thread for more troubleshooting ideas ... http://www.cuda-challenger.com/cc/index.php?topic=91627.msg906382#msg906382

[Road_Runner]

Cleaned, greased with dialectric grease and reseated all the firewall harness connectors, no change.  I started looking around the motor and twice more as I moved wires they just came apart in my hands.  My new engine harness had just arrived so I bit the bullet and swapped it out.  Not only did it have spark, its never started easier!  It even idles more smoothly than ever before.  I replaced the Roadrunners engine harness probably 20 years ago, I don't know why I thought I could live with 40 year old wiring in the Cuda....  Now I just have to replace the rest of the wiring in the car, but at least for now its running & driving again!!

Thanks for everyone's suggestions, they kept me looking until I finally got it done.

Later, Jim

[4Cruizn]

          

[dodj]

 

[Bullitt-]