Electric Fan Wiring

MomsDuster said

I think where the confusion starts is that there are (2) white wires he’s dealing with. One is the switched source for the FiTech that is connected to the ballast on the 12v side. The other is on the wiring to a standard Bosch style fan relay, and in his case is also a switched source. That is the wire that will be to the battery, (or jumped to main power at the relay), as the FiTech supplies the ground for the fan relay.

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And that's why I have typed then deleted 3 different replies here during the past 2 days. Majority of us can't know if Fitech/whatever supplies positive or negative signal to the fan relay coil.
So now we know this fan relay is wired just like a horn relay. Hot goes through the horn relay at all times. The horn switch in steering wheel provides a ground path to close the relay, horn blows.
If he has switched hot to Fitech/whatever that same switched hot can go to this white wire. Or he could use a hot at all times ( like the horn relay ).
I would likely add a inline fuse if I went that route. I just don't like hot at all times. I live with the ones she was born with but those are factory routed wires, most attached with nut and bolt terminals in engine bay. Bulkhead is the exception and we've seen how that works.