Car cranks but wants to start when i release the key but wont run

Sounds like ballast resistor. Make sure it is not in upside down, and has a sealed back. I had an issue with a new single ballast that I had recently replaced. Took awhile to figure out, the back of the new resistor was exposed, usually they come sealed up at the back... After I washed the car, water got into the resistor and after a few miles of driving, the new ballast resistor killed the car. would turn over and fire when I released the key, but died immediatly.

New ballast fixed it. Had a spare in the glovebox and it was my first instinct. *Replace ballast resistor*