1996 Ford Crown Victoria turn signals

If light is coming on when brake is applied then there is a ground wire issue somewhere, either at the signal bulb wiring, signal switch wiring or the brake light switch wiring. You have a flasher for front and rear, so most likely flashers are OK but Front flasher is located right rear of engine compartment while Rear flasher is located center rear of trunk.

Your vehicle has the flasher built into the Lighting Control Module. Here is a short test from the Ford Manual.

Remove lighting control module connector C3.
Using a jumper wire, short Pin C3-13 to Pin C3-15.
Turn hazard switch on.
Are any of the turn signal bulbs illuminated?
Yes
REPLACE lighting control module. RETEST system.

Removal and Installation

Open hood. Disconnect battery ground cable (14301).

Disengage three pushpins and remove lower driver side intrument panel (04320) finish panel.

Locate lighting control module above accelerator pedal.

Disconnect bottom two eletrical connectors from lighting control module.

Remove two screws retaining LCM to bracket and unclip from bracket.

Remove lighting control module from bracket and disconnect two remaining electrical connectors.

To install, reverse Removal procedure. Check lighting control module for proper operation.