1993 Cadillac Eldorado passkey module location

Doesn't use a relay , HVAC power module controls the blower , with signal from the heater and A/C programmer . Free wiring diagrams here
http://www.bbbind.com/tsb-wiring-diagrams-database-results/?type=WD&years=1993&make=45&makeDesc=Cadillac&model=367&modelDesc=Eldorado&system=6&systemDesc=HVAC&subsystem=136&subsystemDesc=HVAC%20Controls&docid=7867005

How to bypass the VATS Passkey II system for mid 1990s Cadillac
I have personally done this and it does work. You will still need the key to turn the ignition switch but you have bypassed the "chip" reader in the lock.

If you need further help, reach me via phone at https://www.6ya.com/expert/steven_a67ead41eb5fc62a

the module is actually the head unit in the center of the dash there is a electronic speed control module that will be located on top the interior heater box behind the glove box unless you are lucky enough too have one that was actually assembled in the states those units that where are located under the hood on the outside blower box passenger side of car close to the valve cover side of the box

On your vehicle, the problem is most likely the TDM (Theft Deterrent Module) It is easily bypassed on the older VATS system that you have

http://vatspasslockpasskeysecurityhelp.yolasite.com/

Look at the sides of ur radiator!
If you see wires connected to ur radiator, that will be the SWiTCH ur looking for!

BODY CONTROL BEHIND GLOVE ON TOP OF HVAC CASE THE ENGINE CONTROL MODULE IS ON THE PASS SIDE UN THE END OF THE HVAC CASE CLOSE TO THE HVAC PROGRAMMER

Easiest way. Go to any auto store, Pep Boys etc, locate the book for the year of your car and write down the wire diagram.

If it is a digital dash you need to replace the central control module located above the gas pedal. If it is not check in the glove box for the fuse panel caddys are known for hiding the fuse boxes in there.

The RSS is located in the trunk on the seat back