I just had a thought that it would be much easier to just mess with the secondary fan rather than messing with both fans per the Total Fan Control rewire. So, primary fan comes on at ECM controlled 220*, I will leave as is, but put a 185* switch in the passenger side head for the secondary fan to come on before the primary.

But, I was just wondering if there is any problem to do this, like ECM freaking out or something... It seems to me though that the ECM doesn't even know about the secondary fan since I don't believe the secondary fan is wired in any way to the ECM.

Any thoughts on this would be appreciated.

 

Personally, if I was to wire it like that, I'd swap out the wiring to each fan so that the one wired to the lower fan switch controls the fan on the drivers side of the radiator.

 

I think that's a bad idea because that would then mean the A/C controlled fan is now on the driver's side. I have read a few posts that say the reason the passenger side comes on when the A/C requests it is so that the A/C compressor is cooled off by the passenger side fan. Doing what you suggest now effectively reduces the cooling effect on the A/C compressor.