Turn signal what: front bulb; rear bulb; flasher unit; fuse???
See "Related Questions" below for each
replace your mutifunction switch (your signal light switch, your high beam and flash to pass are worn out )
The 1988 Ford Taurus turn signal flasher relay switch is located beneath the drivers side dashboard. The turn signal flasher relay switch will be above the brake pedal.
Push the turn signal lever forward
My wipers come on when the turn signal is used - Ford recommends replacing a revised mulifunction switch (turn signal switch)
On a Ford Taurus : The multifunction switch is INSIDE the steering column cover The turn signal lever and hazard flasher button stick outside of the cover
have you tryed all the fuses then check if the bulbs are good
...The Taurus turn signal relay and emergency flasher relay is located in the glove compartment under the fuse pannel access cover. Be advised that the Taurus has two fuse locations, one by the driver side foot kicker pannel and the glove compartment.
The turn signal lever is also known as the multi-function switch. See "Related Questions" below for instructions on removing/replacing it.
Is the bulb blown?
I am assuming you have replaced any defective bulb. If none of the turn signals work, replace the turn signal flasher relay.
Check the fuse for the wipers and replace the turn signal bulb.
1997 Ford Taurus turn signal light bulb replacement: Purchase the correct replacement turn signal light bulb(s) first, before disassembling the vehicle. See sources and related links below for replacement bulb information. Then consult your owner's manual for the turn signal light bulb replacement procedure. As simple as it sounds, the owner's manual is the best place to start for bulb replacement instructions and illustrations. You may want to consider replacing both left and right at the same time in order to keep brightness and color equal (optional).