Review on Alla Lighting 3156 3157 LED Amber Yellow Turn Signal Lights, High Power 4014-SMD Blinker Lamps for T25 Wedge 3457 4157 3457NA 4157NA 5702NAK 3157A 3757 3056 3057 4057 by Isaac Simpson

They were installed on a 2014 Ford E350 for front turn signals. They are very bright and offer all the usual benefits of LED - instant turn on, minimal heat, etc. No problem after a few thousand miles of driving. As with other LED lights, pull-up resistors were required to avoid "hyper flash" problems. - it seems that this new Ford car does not have an independent flasher relay; Instead, flash rate, blown bulb detection, etc. are controlled by a 'smart junction box' that Ford has installed in new vehicles. Presumably it can be reprogrammed to ignore what it perceives as lamp failure, allowing LEDs to be installed without terminators, but it will almost certainly require a visit to the dealer which is much more expensive and likely more time consuming than simply installing a load . resistors.