1974 Plymouth Barracuda won't start

RECKON YOU HAVE A BALLAST RESISTOR BURNED OUT? (THIS IS ON THE "ON" WIRE TO THE COIL).....MY PIC IS A TYPICAL ONE....PIC 1

COULD BE SOMETHING BETWEEN THE (INCLUDING THE) SWITCH AND THE COIL ......BAD SWITCH OR BROKEN WIRE

IN PIC 2 YOU CAN SEE HOW THE "I" TERMINAL WORKS---THIS PIC IS FROM MY 1977 JEEP WIRE DIAGRAM......IF YOU HAVE POINTS, DISREGARD THE ELECTRONIC IGNITION STUFF......I MADE THIS DIAGRAM WHEN I UPGRADED MY CRAPPY, BOTHERSOME, PROBLEMATIC 1977 PRESTOLITE IGN TO A MOTORCRAFT IGN WHICH CAME OUT IN 1979......I HAD TO USE A BALLAST RESISTOR IN IT BECAUSE THE '79 USED A RESISTOR WIRE (THE B.R. NOW PERFORMS THE SAME DUTY)

MY 1946 WILLYS USES/ (USED) A BALLAST RESISTOR TOO.....more in a moment

THE REASON IT FIRES UP WHILE CRANKING IS THE "I" TERMINAL ON THE SOLENOID IS FEEDING THE COIL DURING START-UP (AS IT SHOULD)

"I" DIES WHEN YOU LET UP OFF OF THE KEY---"ON" TAKES OVER.....SUPPOSED TO ANYWAY!

RUN A CONTINUITY TEST THRU THE BALLAST RESISTOR OR "TEMPORARILY" BYPASS IT AS A TEST (YOU CAN JUST HOLD THE WIRES TOGETHER)...........SEE PIC 3...........MINE IS PERMANENTLY BYPASSED ON MY 1946 JEEP, AS I INSTALLED A "PERTRONICS ELECTRONIC SYSTEM" IN MY DISTRIBUTOR..........I KEPT EVERYTHING INTACT, MY POINTS SYSTEM IS STORED UNDER MY BACK SEAT, JUST IN CASE MY ELECTRONIC SYSTEM FAILS.......I CAN BE UP AND RUNNING ON THE POINTS AGAIN WITHIN 10 MINUTES

IF IT IS BAD..........GET A NEW ONE!..........YOUR COIL/ POINTS CANNOT HANDLE FULL 12 VOLTS FOR A LONG TIME, IT WILL FRY THEM........BYPASSING MIGHT "LIMP" YOU HOME FOR A WHILE.....BUT YOU NEED TO REPLACE A BAD BALLAST RESISTOR TO KEEP THE IGN SYSTEM GOOD OVER TIME

......I JUST RE-READ YOUR STUFF......YOU HAVE ELECTRONIC IGN......WHAT TYPE?????.....YOU STILL MAY HAVE A B.R. (OR NOT)

READ "MY ANSWER" ABOUT THE MODULE IN THIS POST

https://www.2carpros.com/questions/1981-lincoln-mark-vi-would-car-run-fine-idol-park-stop-key-turned-off

WITH MY '77 JEEP, WHEN I STILL HAD THE PRESTOLITE IGN SYTEM.......THE MODULE WOULD GO BAD (ALOT) .......THE TEENY-TINY SOLID WIRES INTO DISTRIBUTOR WOULD BREAK (REPEATEDLY)........AND THE CENTRIFUGAL AND VACUUM ADVANCE WOULD EITHER BREAK OR "SLIDE" IN THE DISTRIBUTOR.....(BOTH PROBLEMS TWICE).......ALL OF THIS IN A 5 YEAR SPAN

SAD THING IS, IT RAN, IT LACKED POWER AND ECONOMY.....I FIGURED OUT THE ADVANCES DID NOT WORK USING A TIMING LIGHT

.......I GOT SMART AND INSTALLED A MOTORCRAFT DISTRIBUTOR AND REWIRED FOR THE MOTORCRAFT MODULE........THIS WAS NOT HARD, I USED A REMAN DISTRIBUTOR AND A NEW MODULE (BOTH ABOUT $80 AT ADVANCE AUTO PARTS), I CHOPPED OUT THE WIRING AND CONNECTORS BETWEEN THE 2 OUT OF AN 80's FORD PICKUP IN THE SALVAGE YARD (THEY GAVE IT TO ME)........I HAD TO SHORTEN THE WIRES SO IT LOOKED NEAT IN MY JEEP

IF YOU WANT ASSISTANCE WITH ATTEMPTING AN UPGRADE, LEMME KNOW....I MAY BE ABLE TO MAKE A DIAGRAM SHOWING WHAT NEEDS TO CHANGE

KEEP ME POSTED!

THE MEDIC

I JUST PROOFREAD MY STUFF

I MEANT TO ADD IN AT THE TOP THAT WHAT I WAS SHOWING YOU WAS FORD/ JEEP. OLD STUFF LIKE "OURS" WORKED VERY SIMILAR. YOU MAY HAVE TO "TRANSLATE" MY JEEP STUFF AND SORTA FIND THE PLYMOUTH WAY

THE MEDIC

I agree with CJ. It sounds like a bad ballast resistor. The resister is designed to allow a full 12v to get to the ignition when starting (key in the start position) but once you let off, it should send power through the resister and cut the power to around 9v. This protects the ignition system and allows it to last longer.