Every time I look at the JL forum, the XJ flasher issue reoccurs. While the Charlie Nowlin FAQ is correct, it doesn’t directly address the flasher replacement/interchange issue directly.
I believe Doug is on the right track; it sound like the 5-pin replacement flasher is just the wrong part. When I did my 86 XJ6s3 LED upgrade a few years ago, I researched the flasher issue extensively.
- Only a handful of aftermarket 4-pin flashers are compatible with the XJs3 using incandescent bulbs.
- I didn’t find any aftermarket compatible flashers that worked correctly with LEDs, so I built one (a completely separate topic).
- I didn’t find any compatible 5-pin flashers.
The vast majority of 4/5-pin aftermarket flashers are designed for 2 indicator circuits (eg front circuit plus rear circuit). Those will not work. You need:
- pin 49 = power from hazard switch.
- pin 49a = stalk and lamps.
- pin C = pilot circuit for dash indicators. This is different than a 2nd circuit; there is no bulb fault detection on a pilot circuit. On the DAC1731/TBB44. the pilot circuit signals bulb failure while the remaining exterior lamps flash normally.
- pin 31 = ground.
Compatible flashers include Hella TBB44 (perhaps some NOS available), Lucas SFB191, Rover PRC8864, and a few others.