1993 Towncar ABS light on constantly?

The airbag module will flash out the trouble codes through the airbag warning light on the dash.

Step 1 - Turn the Key ON

Don’t start the engine, just turn it to RUN. The airbag light will come on solid then go off, each code is a two-digit number:

First digit = number of flashes before a long pause
Second digit = number of flashes after the pause

Example:
Flash-flash-flash … pause … flash-flash
= Code 32

Code Meaning
12 Low battery voltage / recent power loss
13 Airbag circuit short to ground
21 Safing sensor not mounted / open circuit
22 Safing sensor short
32 Driver airbag circuit high resistance (clock spring issue)
33 Driver airbag circuit open (bad clockspring)
42 Primary crash sensor feed open
44 RH front crash sensor fault
45 LH front crash sensor fault

Please let me know what code you have.

I was asking how test the ABS?

Yes, you need to test the ABS, you must run the codes first that will tell us what is wrong. Please recheck the post above.

lol, wow I got off the side on that one, my bad, yes the ABS system light comes on when a wheel speed sensor goes out in most cases. On the connectors jump these two together:

Triangle connector: Pin E (top single pin)

Two-pin connector: Black wire (ground)

ABS Code Retrieval Procedure

Turn key OFF.
Turn key ON (do NOT start engine).

The ABS light will begin flashing two-digit codes:

Long flashes = tens
Short flashes = ones

After a pause, additional codes will flash.
Example: Flash… Flash… (pause) Flash… Flash… Flash… = Code 23

Popular codes

Code 11 - Left Front Wheel Speed Sensor Fault
Code 12 - Right Front Wheel Speed Sensor Fault
Code 13- Rear Axle Speed Sensor Fault
Code 14 - Wheel Speed Sensor Signal Erratic / Intermittent
Code 15 - Mismatched Wheel Speeds / Out-of-range comparison

Let us know what you find.