Hi Guys, new here. This site came highly recomended by a couple of friends. I may have a "one of a kind" issue. I own a 1989 Cady, 4 door Deville, v-8. This is my summer car, I have owned it for 10 years, only has 121,000 miles, very few problems untill now. About a month ago I was driving in heavy rain with the air conditioner on to keep the windows defogged. All of a sudden the heater started blowing hot air, I lost all my dash read outs, except for the time display. The "service engin soon" light came on and a C appeared where the fuel gauge is and where the tempeture gage is. It still ran fine so I took it to my local garage. This guy is very good, has worked on my stuff for many years. After working on it, on and off, for three weeks, he has given up. He thinks its a ground problem. He ran seperate wires to everything he could find with no luck. He even switched out the computers from another Caddy like mine. The problem is not consistant. I have been driving it for a couple weeks now. Most of the time when I start it up, the service engin soon light is on and the air conditioner is blowing cool air and the C's are showing as discribed above. One time I stoped to visit a friend for about a half hour, when I started it up to leave, the dash readouts worked fine for about 5 minuets, then the heater started blowing hot air, the service engin soon light came on and the C's appeared. It blew hot air the next two times I drove it, then on the third time it went back to cool air blowing. Also, I had filled it with gas and tried to set the tripomenter. It would not reset untill all the dash readouts worked normally. This car is my Babby, I hate to get rid of it but if I take it to the Caddy dealer I'm sure the fix will be more than the car is worth. Thanks for taking the time to read this and I hope someone will have a solutation for a fix.