Well, first of all, it’s a 3.8 V6, not the 3.0 that was in so many of Ford’s other cars (it is the same engine that was in the Mustangs of that vintage, and there was FWD variant in the Taurus and Windstar).
There is a relay group called the Constant Control Relay Module, and I’m assuming that this part is your problem. It’s not cheap, but it’s cheaper than a PCM.
The Thunderbird & Cougar Club of America will have a definitive answer:
Best of luck!