Well like the title says all of a sudden my brake lights (all of them), my passenger turn signal (blinks really fast and one of the bulbs in the back aren’t working, blubs fine but just not illuminating), and my cruise control aren’t working. It’s a 1993 STS thats not had any problems up until now and seeing as I'm a poor high school kid taking it to a shop, especially if it’s a Cadillac one, is hopefully a last resort. If it's something that can be fix mechanically then I can do it, I just need to know what it is lol....So anyone have an idea?

Pull the rear bulbs and check the sockets for corrosion.

Ya that's what I was thinking too, but there was none to be found...lol I think this was the only time I've been disappointed to not find rust somewhere :p

Check the grounds.

ranger, are there lighting processors in these cars?

Not sure, but never heard the term before.

ranger, are there lighting processors in these cars?

I dont really think there is a "lighting processor" necessarily in the term youre thinking, though the way that the lighting is controlled may have something to do with it.

The car that had a sophisticated true lighting control system around that time was the Allante.

i mean, is there a lighting control module

I am used to calling them processors from crown vics, sorry.

One common thread between brake lights, turn signal and cruise is proximity of the switch wiring to the steering column. If they share a common ground or connector that has been disturbed that could take out all three. On my 90 CDV there was one big monster connnector at the base of the column. I am assuming you've checked the fuse(s). Two questions and one suggestion:

1) Has any work been done under the dash (particularly on the driver's side) recently?
2) Is the cruise control dead electrically or mechanically? (Does it not come on, or does it come on but not hold speed)

Start with the brake light switch on the brake pedal and check for power there and verify the switch is passing that power aft. At least that way you can start working forward or backward.

No there hasnt been any work done under the dash and the cruise control is dead electrically, is just doesnt com on period. Also the brake light switch doesnt get any power. At first I thought this was the problem so I replaced it, but low and behold, still no power.

I think the next stop upstream toward the battery should be the fuse block - brake lights should be from a 'hot at all times' fuse. Seems like it has to be fuse or connector. FSM would be helpful since they have not only the wiring diagrams but connector locations and pinouts.

I think inner stop lights onto the trunk, fails very common on those cars .A friend of mine also complaint about one of the flashing lights blinking fast .The problem was driver side inner stop light wasn't lightning on when you apply the brakes .So, I just tapped on the faulty one with my fingers and it worked lol
No magic I think some corrosion can cause such problems as well

Ya I also thought fuse or relay but none of them were burnt out. I checked under the dash for any loose connections or shorts but I didnt find anything out of the ordinary. I also re-checked the brake switch but it too was fine. So again I'm back at square one lol

I think your reading to much into this,I changed my socket in my 97 sts just last week,it was also blinking fast,it was the socket in the trunk lid, it was not making a good connection,take lens out and fiddle with bulb with the turning light on,it will probably connect.

could be a bad R.S.S sensor or something like that. I don't remember the name. Mine went bad in my 99 and it killed all electronics in the car. Windows, Locks, Horn, Turn signals and tail lights.

Hummm...Not sure its an R.S.S switch, lol i dont even know what that is, because all the other electronics in the car are working well, just the damn brake lights, turn signal and C.C. Also about the light sockets, yes that was checked too. I went through all the lights in the front and read and none of them were burnt out / had corrosion. I also re seated them a few times to ensure a good connections but of course, my luck lol, that wasnt the problem.

You need to find out where the voltage is stopping. Start with a test light and see if you have power at the brake light switch. If yes go downstream to the trunk area. Plug the test light in a socket and use a known good ground to the chassis. Check both the brake light and turn signal sockets. If the test light works with a different ground than the bulbs you have a ground problem. If you have power at the brake light switch but no juice astern there is likely a connector problem somewhere in between. A factory service manual with the wiring diagrams would be your best bet.

I got the service manual so thats not a problem, also I did check the brake switch for power and ground, which it has both of. The next thing I'm going to try and check is the wire that goes from the switch to the e.b.c.m or w/e its called....*sigh*..cars...not sure if I love 'em or hate 'em