Gentlemen I posted this just before the migration to the new site. It appears to have been lost in the changeover (which I was warned would probably happen)...so I am reposting. Hope thats OK. The Bike: A 2004 WR450F which has an aftermarket Acerbis headlight unit on it. This was on the bike when I bought it and it has two 35 watt household type halogen bulbs in it. The type you can buy at any Home Depot for your overhead light fixtures. I rode the bike like this for two years and never had a problem with the lights. The Problem: Early last season I started to blow headlights. I replaced them and then discovered during the next ride that they were blown again. I replaced them again and started the bike and tried to figure things out before I went on the trail. They would brighten as I revved the bike and then dim on throttle back....they have always behaved like this and would normally reach a point of max brightness and all would be well. BUT...as I kept revving the bike this time I noticed that they kept getting brighter and brighter until they blew...the same thing would happen to my tail light. Apart from this the bike would run exactly as it always did...very well. I finished the season riding with no lights...the police where I ride thankfully cut off road vehicles a lot of slack...I have to ride on the highway to get to the trails. So my quest for information is in two parts. Question #1 -My thinking is that my regulator/rectifier is toast. Does this make sense? Do they just stop working properly? Can anyone think of another reason for the problem?? Going on the assumption that it was a regulator/rectifier issue I traced the wiring harness for it, and it disappers completely between the rads and almost appears to go right into the middle of the frame upright (where the oil dipstick is). It disappears so completely that I am unable to see the two multipin connectors that I understand are on the end of the harness and that snap into the main harness I presume. I have looked at a new reulator unit (I was told it was for a 2004), and the harness is only about 20 inches long..which corresponds exactly to where it gets buried in the rats nest of wiring/cabeling between the rads. SO....Question #2...does the harness in fact end at this location with two multipins and they are just out of sight?? and is it necessary to pull the rads off in order to hook up a new one? I am trying to avoid pursuing the wrong solution to the problem and also avoid pulling the rads if I don't have to. Thanks guys for any and all assistance...much appreciated.