Retired Nuclear Engineer
2006 GL1800 Comfort/Navi
I know the LCD displays have been discussed quite a bit, and I've read them all - trust me. A couple of years ago, my LCD screen started getting dim to where the backlight was visible only in low light or at night, even with the dim setting on the bike at max. I ordered a replacement (foreign) and changed it out after sitting on it for about 4 months. There was no improvement; it wasn't any brighter. I ordered another supposedly OEM replacement, again from overseas, and again, no improvement. I did some research, and I ordered just the CCFL tube from a US manufacturer, and I replaced just the tube, again with no change in brightness. So my troubleshooting background tells me that if 4 displays give the same problem, it's probably NOT the LCD display, but the power being supplied to the CCFL tube. I've gone through every relevant schematic in the GL1800 Electrical Troubleshooting manual, and the "Combination Meter" as they call it has inputs and outputs, but they do not provide a schematic of what's inside the "Combination Meter", which contains the gauges and a circuit board. My theory is that the circuit board provides the power for the CCFL tube, and is probably not putting out as much power as it should. (And on a side note, the power to the CCFL is NOT DC.) I would LOVE to be able to get hold of another circuit board, because I'm sure that's most likely my issue. I welcome any input!