Front Turn Signals, 3.8 Converted to Negative Ground, 4.2 Series I. Requires flasher unit 17-1120. Now you can upgrade the safety of being seen with these nifty Light Emitting Diode (LED) lamp inserts. The difference in brightness is incredible and installation is simple. Because LEDs draw so little power, you will need to replace your flasher unit for your turn signals to work correctly.