Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
Perhaps the 500 is wired differently? Would be interesting to test the 500 with a multimeter to see if they do change polarity. The usual way to wire LED's is with a fused direct live feeding into 2* 12v relays, then the indicator connectors 1 to each relay switching the output to the led lamp. A lot of work to just change an indicator repeater bulb to LED. I took mine back out again and re-fitted a standard bulb. Not actually sure why they reverse polarity, like you I couldn't understand from the wiring diagram how it was happening, but it was. Maybe someone like Ash could throw some light on it.
RoyI am really interested in this question. I am no electrical guru but I notice the 500 uses a 2 wire flasher relay whilst the 550 uses a 3 wire relay. Be most interested if someone can clarify this point