There are 3 relays on my '91 Z behind the brake booster in an L shape. The middle one is the fuel relay, shorting the green wire to ground makes the engine stall (good for a kill switch maybe?). The driver's side relay (which has a green/wht wire) controls the driver's side fan; run it to ground to turn that fan on. The relay on the passenger side, turned 90 degrees facing the engine, was the secondary fan relay. It had no green/wht wire. You need to run the GRAY wire to ground to have the passenger fan kick on.

With one fan, 180* stat and two tranny coolers for the air to get nice and hot through before it hit the radiator in stopped traffic (95* in the noon sun), my temp was a steady 220.

With both fans, my temp stays at the line between 100 and 220 regardless of if I'm moving or not.

I don't know if this was posted, but I don't recall ever reading a post about a gray wire and I abuse the hell outta that search button