the car is a 86 420 sel. I also want to add that when I start the car at temperture below 80 the fuse for the ac unit blows. The engines dies on the road most of the time at night or the day when radio or ac is on. I drove it tonight with both off and had no problems. Since this problem has started the rpms are very low even at 65 mph. Engine will die at any speed. Any ideas of what could be the problem or problems.