Possible Ingition Switch Issue

[URChallenger]

Hello all,

I am new to the forums and so far I have found a enormous amount of information.

I recently aquired a 71 Challenger with a slightly modified 340 and have a unusual issue with the ignition switch.

When I crank the car over it starts right up, but once I let go of the key, the car instantly dies. If I hold the key between the on position and cranking, the car remains running.

Do I have a faulty ignition switch or are there any other possibilities that may cause this issue?

Thanks in advance for your help!

 

[moparmarks]

Yes I've had this happen on the couple 71/2B. Switch would not stay in the run position. Replaced the switch and all was fine. This on 2 different cars.
Usually it is the ballast but sometimes is the switch.

 

[nothingbutdarts]

As moparmarks said, check the balast resistor. Usually when you let off the key and it dies that is a good sign of the resistor being bad. Just disconnect the wires to the resistor anmd ohm's check it. If it's bad it will be open. It should read about 1ohm or 1.5 ohms.

 

[URChallenger]

Thanks for the quick and detailed replies guys. I will look into it and let you guys know how it goes. Hopefully I can get around to working on it soon.