1969 GTX only runs with starter engaged; quits in run position

[minnesota guy]

My 69 GTX ran fine when I put it away last fall. Now it will only stay running with starter engaged. It dies when it goes to the run position. Newer electronic ignition Mopar distributor kit installed.
Narrowed it to Switch or ballast? Although the ballast doesn't have alot of time on it.

Thanks.

 

[moparcanuck]

Ballast resistor.

 

[RJRENTON]

I agree with the previous person....ballast resistor. I believe if you found a replacement with an OPEN back, rather than the sealed unit (manufactured by Dale) they generally last longer because they run cooler. The OEM resistors used with points were 0.5 ohms while the new resistors are 0.1 ohms. The transistor on the control box switches the coil current off, when the pick up coil in the distributor generates a pulse that controls the transistor. The resistor limits the coil current to a safe value to prevent zapping the switching transistor. Transient voltages are supressed by diodes and capacitors inside the control box. The original system used a 5 wire harness and a 2 element resistor. The main resistor was 5.0 ohms to operate the control box and the other half was 0.5 ohms to limit coil current. The newer 4 wire system uses a 0.1 ohm resistor snd the control box redesigned to not need the 5.0 ohm resistor.
Cheers,
RJ Renton

 

[minnesota guy]

Thanks. It was the ballast resistor