Converting to Amber Turn Signals
CAUTION: The wiring steps mentioned below were on a (very early) 1989 SHO. Consult a shop manual if in doubt as to which wire is correct for your vehicle. I don't want to be responsible for anyone driving around without taillights, flashers, or any related problems.
These brake light assemblies are for the first gen (1986-1991) Taurus only. They will not work on later cars.
Modify the Multifunction Switch Wiring
I have always really liked the look of separate amber turn signals on the rear of a vehicle, and had been envious of the '91 guys as a result. How hard could it be to convert? After all, amber turns were available on certain early Taurus models.
For this conversion you'll need a set of donor lights (91 SHO or some earlier LX models), complete with bulb sockets.
The brake lights do double duty as turn signals. So, I needed to figure out the wiring. As it turns out, the flashers provide input to the multifunction switch (MFS), and that output goes to the taillights. The brake switch signal piggybacks on these circuits. Cutting the brake switch input to the MFS renders those circuits flasher-only without affecting the brake signal to the center high mount stop light (CHMSL).
Modify the Wiring in the Trunk
Locate the brake/flasher circuit on the old bulb socket. Cut the wire and splice it onto the amber light's input. Splice the ground from the amber bulb into the ground circuit. For the brake lights, you'll need to tap into the CHMSL circuit under the package tray. This circuit was red with a green stripe on my car. Run a wire from here down the wiring loom on the driver's side of the trunk. This wire should be spliced into the red light input.
Repeat for the passenger's side.
Amber rear directionals.