Nice project .I have been thinking of doing this for some time now. Did you have any problems fitting the fan .And my way would be a simple switch on the dash so i could work it, as , and when , the temp was on the up . I was reading on the web about this guy that new all about the merc engines m103 m102.And his words were to change the thermostat to a lower rating so the water circulated quicker to keep it cool . Can i ask what fan did you use please .And can you post a diagram of wiring .