Hi. I have a 1990 Cadillac Deville. Recently, the display gauges for fuel and the temperature in the climate control center failed and began permanantly displaying only the letter "c". Now, when running the car, the interior blower goes on high, does not warm up, and I'm unable to make any changes to the climate control settings. I checked the fuses, everything looked fine there. Any help you can offer will be greatly appreciated. Thank you.
Recently, I have been barraged with old car questions and I hold myself out as being pretty darn accurate, but to be perfectly honest, I do not remember the correction to problems such as yours.
What I would do if this were my car is get the factory manual with all the diagnostics. Besides, if you are keeping the car for any length of time, things are going to go wrong on a 21 year old car and either you can fix them, or you can share with your mechanic, who may not have this explicit information.
It's $30, but you download for a year and even in the diagnoses of your current problem, takes out all the guess work. http://www.alldata.com
You could spend hundreds and never find the factory manual for the car.