Cadillac Repair: electrical problem, fuel guage, electrical problem

Question
I own a 92 seville, 4.9l.My problem is I have no control over my instrument cluster.The fuel guage works, the rpm guage works. I cant control my heating & A/C.It's like the PCM is either not getting signals from the sensors or the PCM just isn't sending them to the dash.The service engine soon lt. is on also. I tried to jump out the thing where the mechanic can plug in his tester to get the fault codes, but I didn't get anything.when I start the car it dont say"monitoring systems" anymore either.the car runs and drives o.k.. I also had a short somewhere in the brake lts. is it possible for a short in the column to affect all of these components?.I did notice a little sizzle of smoke a while ago,it looked like it was coming out of the column. then a short time later is when all this happen. appreciate any help you can offer. thanks

Answer
Hi Steve, There are too many checks that need to be done to eliminate the good from the bad parts. Turn signal switches in the column cause smoke more often when useing the turn signal but the brake light circuit does go through it. Sorry I can't be more help. Bill