Are you converting your headlights to HID or LED and having an issue with them not turning on or only one side working? This is a very common problem on older cars, trucks and SUVs that use H4, 9003 and HB2 light bulbs.
These are simply designed as a ground switching module to create a simple plug-and-play solution for most vehicles using an industry standard H4/9003/HB2 headlight plug with a switching ground when going from low to high beam.
These polarity converters are made to simply plug in between your vehicle's stock H4, 9003, HB2 factory plug and to your aftermarket HID kit and or LED bulbs to function without issue.
One pair of polarity polar ground adapters
All vehicles that use H4, 9003 and HB2 bulbs
Blue Wire – Ground Black Wire – Ground Red Wire – Power