What a difference!

[Eveready1100]

To my surprise, the kit I bought worked perfectly with my RLU! High worked, low worked, the high beam indicator worked, it changed from high to low exactly like it did before (just the light was a LOT brighter!). That put me a bit of a quandary because if I kept the RLU, then I wouldn't have to modify the wiring at all. But, I WOULD have to find a new home for the ballast.

My kit worked fine with the RLU still in place when first installed. It was only when I took the bike for a ride that the fun started. That was when I discovered the RLU had to go. My only mod was to unplug the RLU at the connector and plug in a spare bridged connector I robbed off my old harness, which left all the bikes wiring unaltered so I could revert to the standard setup if need be.
What I figured happens here is that The HID draws a lot of power when first lit up ( it does have a 30 or 40 amp fuse in its harness for a reason) and still draws a fair bit until normal operating temperatures are reached when the current draw tails off. That would explain why the RLU didn't play up initially. Only after about 10 minutes on the road did it make its presence felt.

BTW, a tip if your HID quits while on the road. Hasn't happened to me, but I've thought about the event, just in case. Carry a H4 bulb as a spare. In an emergency, pull the fuse from the HID harness, unplug the 3 pronged headlight connector from the harness and connect it to the H4 bulb you've just refitted in the headlight bucket and it'll work as normal to get you home without having to rip any bits out.

[Lonerider62]

I really don't know that much about HID kits mainly because my FZ1 has excellent stock lights but I have read that because of the amount of current that HID lights draw, the stock wiring should be used only as inputs to a relay system that then switches 12V directly sourced from the battery. I do know that with some of the early systems fuses were popping like popcorn and some stock wiring was turning pretty black as it fried. Another early warning I heard about was to stay away from the el'cheapo Chinese kits. Does any of that still apply to the kits available now?

[crazy steve]

If you live in the US, there's almost NO legal HID conversions, and certainly no inexpensive models. They're illegal in every state unless you have one of the very few DOT-compliant versions, and a few states are getting nasty about prosecuting people who have them.

The only motorcycle-legal systems I've ever seen were for 7" round headlights, you had to change the whole light (including the lens assembly and shell because these won't fit in a stock one), and cost over $300...

[LoHo]

Another minor point: as most states require bikes to have a lit headlight constantly, the RLU will keep you legal if you only ride during the day, as in commuting.

[cywelchjr]

However one of the failure modes of the RLU can kill your headlight with no warning light. Frankly just making sure your headlight is good does the same thing.