1972 dart - stopped running while at 50 mph ? no warning

67Dart273 said
SO...........If you "check spark" by jumpering the starter relay.......you are using the "run" circuit and NOT the bypass circuit. THIS MEANS that voltage is greatly reduced, because you are powering the coil from the "run" circuit through the ballast, and as the charging system is not working, that voltage is now down to "battery" AND is further loaded down by the starter. You will be lucky to get 5V to the coil if doing so
SO............Try to check spark by using the KEY to crank. "RIG" a SOLID core wire to the coil tower (not radio resistor wire) and wire that to a test spark gap. Lisle makes a decent one that is adjustable, for about 10 bucks. You should get nice snappy blue spark at least 3/8" and more likely 1/2" long

ok , so i tried to check the timing , with a remote starter switch , but could not get the timing light to flash much at all , one or two random flashes , and nothing . tried two different timing lights a few times each , same result or nothing . i feel like i am doing something wrong . so i could not find a solid core wire , so i used what i have . i tried to check spark at first with the remote starter . zero from coil or plug wire number 1 . then i re read what you said a few times ( i takes me awhile ) and tried with the key . from what i could see looked like an ok to good spark , had the gap at about 3/8" , from looking between the bottom of the hood and cowl and with sun in the mix . heard a zap zap sparky sounds too . tried the same thing by putting the wire with tester in the cap where number 1 goes . got nothing , no spark , no happy sounds . then pulled the cap , pressed the remote starter , rotor is spinning , points are opening and closing , but no sparky goodness from those either .