Review on 💡 Auxbeam H4 9003 LED Light Bulbs - High-Performance 8000LM 6500K Cool White - F-S3 Series 9003 HB2 P43T Conversion Kits - With Fan & EMC - Halogen Bulb Replacement - Pack of 2 by Michael Pickering

Absolutely terrible you get a ticket. Bought H4 headlights for Toyota Tacoma. Ring adapters fit perfectly. Installation is easy. The lights are very, very bright. The problem is that these are the same F-S3 series lamps as all lamps in this series. I installed a similar set in another truck. The adapter ring changes, but the position of the LED in the bulb does not change. The H4 bulb uses depth to determine the focus of the beam between high and low. Hence the additional DOT rules for this lamp. If you try to use this stock bulb in an H4 light you will definitely get a high beam. The low beam only works if the high beam switch is on and the high beam is already on. I'm considering swapping the wires on the harness but this will only light 1 of the 3 LEDs and will produce faint lows to complement the nuclear highs I have now. UPDATE - I disassembled the lantern. You cannot switch high and low frequencies directly. The drivers are tuned to power the "low" LEDs no matter what. Swapping wires means everything gets power. Turning on the "high" lights with the wires mixed up will result in the "high" lights turning off, meaning you're still blinding people on the road, but you can't see what's fifty feet in front of you is. All vision is probably related to heat. The LEDs make reasonable contact with the aluminum case, behind which the heatsink is located. But to keep the heat away from the LED driver, the manufacturer simply applied a HUGE bead of heat dissipation compound to the regulator. The driver might as well be sitting in a puddle of isolation with that much goo. So. I will resort to halogens until I find a suitable substitute.