[cw362]

I have a 1992 Oldsmobile Royale LS with a 3.8L engine the dash is all computerized.
About a month ago, my car started reading HIGH VOLTS on it. I look on the dash guage and it's getting 20 volts from the lines. I've replaced the alternator 3 times and it still does the same thing. I've cleaned the battery cables off and this doesn't work. While running, it will Idle around 1000-2100 RPM on the digital tacometer. Also when pushing on the gas with this event occuring I have to press down on the gas more then I would just to get the same power. This problem happens about 80% of the time I start the car, then it will refuse to start up again afterward until I unhook the battery cables and re-attach them after a wait.

I've cleaned the two grounds that are in the engine bay and nothing happens. What next should I do? No one seems to be able to help solve this problem. If I should check a cable, which one and where? if I should replace a part, which one? Lastly, I'm looking for the ground under the car near the transmission, can anyone tell me where this one is, and if this is a possible fix to the problem?