Originally Posted by kymudder08
its a code 18 i guess. flashes once, pauses, then flashes 8 more times
2007 F150 - Lamp Fault Code 18 is for a problem with the Passenger Airbag Disable indicator light. Take a look and I'll bet that it is no longer working.
First - make sure that the everything got plugged back in correctly after the audio work. Second - I'm not familiar with the indicator in the F150 but the Ranger PAD bulb is very sensitive to rough handling. The Ranger bulb is not available separately from Ford but a suitable replacement can sourced from an electronics store and soldered in. Maybe the F150 is similar.