need a little help with a spal wiriring harness...

The pair of spals are wired together with a little clip connector. That is self explanatory. The clip has a black lead coming off of it -- I assume the ground. At the other end there is a large red wire that obviously is intended for the battery. There is a relay in the middle that has a small black lead (ground obviously). There is a gray wire coming off of the relay that is clearly designed to swith the fans on without overloading whatever power source is used to switch it on. Does this little gray lead go to the hot side of the intercooler pump or somewhere else?

second part of this question is would I want them to be on all the time or should I somehow tie them into hot that kicks the electric fan on so they only come on when the system is calling for more cooling?

thanks!