Have a 2011 Taco TRD with factory DRL/turn signals. The stock bulb is a 4157 NAK dual element. I replaced them with switchback LEDs that are supposed to be white on DRL mode and then turn yellow on flash. The problem is that they are amber all the time in both DRL and turn modes. The Taco socket is a "CK" type and has 2 wires (not 3). I have tried reversing the bulbs in their sockets, have installed 6 ohm load resistors to prevent hyper-flashing (They work fine-no hyper-flashing). I tried wiring the load resistors one side from hot, the other to ground and between the 2 wires in the socket-still no white, just amber. Is this an inherent problem with Toyota? I have seen a lot of other comments with similar problems. Does anyone know of a switchback that does actually work (change color) in the Tacoma? I contacted the manufacturer (GT in the box), but they could not resolve the problem and just want to refund the money I paid for the LEDs.