I can't recall exactly where to purchase one but you may look at simply bypassing the factory system for turning on and off the fans. Power your fans directly from the battery and use a secondary external thermostat that would turn on the power (relay). At the very least you could do this for one of the fans. If you want to go crazy see if Flexlite offers a pusher fan that you can place in front of the radiator and wire up. Other than that cut the power lines that currently run to the second fan. Then splice the second fan into the wiring of the fan that does come on.
There is always another way.
