No spark.

[ammo]

73 challenger 340. Sat for about a month,, today no spark out of wires or coil.   Not sure where to start..  anyone have a list to get me started trying to figure it out?    I've had some issues lately so concentration has been an issue.  Any help would be appreciated....

[70chall440]

Check for power at the + side of the coil in the run and start position.

Cars don't typically break by themselves, however it can seem that way. Many times electrical contacts corrode over even a relatively short time or something comes loose.

While this is frustrating, it shouldn't be all that difficult to diagnose and fix. There are lots of youtube videos, internet information and this forum not to mention a host of manuals out there. 

[ammo]

Ok.. kinda weird...  no spark for days.   Put on a new ballast resistor just cause I had a spare anyway.. old ballast had some cracks in back of ceramic..    still no spark...  read 70chal 440 comment so got the logic probe..       had wife put in run position..   6.5 volt at coil.  Had wife crank it and it started immediately which it never does on a good day.. coil reading 8.2 volt on + side when running.. 

So,, either
1). Intermittent issue decided to start for me now to make the wife look good and me like an idiot..
2). When I slid the negative and then positive connectors back a smidge on the coil to get the probe to touch metal.  That made the difference...so maybe crimp em a little tighter then slide back on or use screws....
 
Was thinking it may be the pickup in the distributor but I would assume if it was that that's usually not an intermittent kinda issue...   more when they fail, they stay failed..   correct?   

Anyway,, going to drive it around a bit..    see how she does....   

[70chall440]

More than likely 2 things occurred,

1. changing out the BR cleaned up the power flow thus providing more juice to your system.

2. by pushing the connectors on "a little" broke the corrosion and made good contact.

If the pickup in the distributor goes bad, you correct in that it typically stays bad.

Congrats; when you can spend some time cleaning up all of your contacts. If I understand you correct, you are using push on terminals on your coil? While I know they were used on factory cars but they were never a good idea from the beginning. Get some good ring terminals and solder your wires.