Cadillac Repair: 1989 Cadillac Fleetwood - A/C problems and more, 1989 cadillac fleetwood, cadillac fleetwood

Question
Recently the A/C began to act strangely. It might do any one of these three things in a random way. First it might work correctly. Then it might not work at all with no air being moved. The third way it worked was for the air to come out of the defrosters at the top. Then it might begin to work correctly or it might stop working completely. We've noticed it might work and a bump in the road could change it. It might work when we turned the car on, or it might not. After checking with a mechanic I followed their suggestion and looked at the programmer box. Since I have two other programmer boxes available, I took the one out of my matching Cadi and put that in. The A/C worked the same. I left that programmer box in. But after putting it in other problems have developed. Now when you turn the radio off it's not off and pulses on and off as does the clock and the rear antenna which goes up and down about three inches. When the car is turned off this still goes on. It has drained the battery so now I remove the battery cable so the car is completely dead. Any suggestion would be welcome. I did take it into a dealer whose service department couldn't replicate the problems when they drove the car so they say they can't work on it. I offered to drive it until it did show a problem but if it did, then couldn't suddenly pull a mechanic to work on the car. A lose-lose situation.

Answer
Check the several BLACK ground wires in the engine compartment next to the 2 horns to make sure they are clean and tight.

Also check the BLACK ground wire attached to the alternator for being clean and tight.

Check the wire connectors at the BCM computer to make sure that they are clean and tight which lies flat on it's side above and to the left of the programmer.