I have an IC-706 MKII in a 1994 F-150 powered by a 5-liter V-8. I have no ignition, fuel pump or alternator noise in this vehicle and never had. My XYL's Explorer is another story. If you are sure that it is ignition noise, I would check the wires. The resistance type wires in common use these days should measure 10K or so each. Good luck in solving the problem. 73 de Warren (WM2Z)