I am not sure how your wiring is set up, but I think you should have a "direct circuit" to the coil which by-passes the ballast resistor on starting, and then switching to the "run circuit" which uses the ballast resistor. Maybe you need to "hot wire" your truck? Check your ignition wires. Somebody will correct me if I am wrong.

Always get a 2nd opinion, especially if I am the source of the 1st opinion.