i need some pics of how to do this on a 98 f3 as it heats up while sitting. the fan does turn on but not till its about 3/4 ways up

 

I wouldn't mess with it, personally. If it turns on before overheating and keeps it from going any higher in temp, it's working exactly as intended.

 

what i do is leave the fan switch connected (plug with a wire on your rad.) but tap that wire (which just grounds the fan circuit when hot) and run it to a switch then a ground so now YOU can turn it on OR the switch can whichever happens first. then if you aren't paying attention it'll still do it automatically.

 

I don't think my fan has even come on since I've had the bike, It never really gets above a bit over 1/2 way up the gauge. The bikes seem to have a pretty efficient cooling system, as long as the coolant is maintained. Then again, 90 degree+ days are coming, so I'll report back then...