1970 challenger starts but will not stay running when you let off key

[Black70RTconvertible]

 INGSTION SWITCH IS GOOD Balast is good bulkhead conection is good runes in but not in run

[Chryco Psycho]

If you have a spare ballast try it that is the cause 90% of the time .
 check the dark blue wire at the ballst for 12.8 V feed if not trace back to the firewall connector or the column connector

[Black70RTconvertible]

should it be at 12.8V always, when the key is in run possition or only while the car is running? the car will start and run while the key is in the crank position but once the key moves toward the run position it will die.

[Strawdawg]

should be hot when the key is ON

[Chryco Psycho]

run position the blue wire should stay hot

[Black70RTconvertible]

Traced blue wire, cleaned all terminals(bulkhead, coloum...) an it was working for about a day, then went to use it today and had the same problem. now cleaning it isent seeming to do the job. any other suggestions?

[dodj]

Does the blue wire have 12 vdc on it when in the run position?

 From the last post, it seems like connections is your problem.

[Black70RTconvertible]

Think i got it figured out. the bulkhead connection is the issue. Thanks for all the help

[Chryco Psycho]