Electrical wigging out

[ACgtp97]

97 GTP- DIC,HUD, flickering off and on headlights get brighter and no power in first gear, with wierd whinning noise. issue comes and goes. Already replaced bat and alt, cleaned terminals and grounds added an extra ground to ECU.
This thing is driving me nuts and has my mechanic stumped, can anyone help?

[rossscrappy]

ignition switch for your electrical problems...worn tranny for the power...your car is supercharged hence the whine...these cars are like hormonal women you knever know what is going to piss them off.

[mikedinthecity]

there has to be sumthing shorted to ground which is making the alt whine b cause of the load. look by the starter, there are a bunch of pos wires there make sure none of them r touching engine or are grounded. also check the pos cable by the battery and the pos wire foir the alt, follow them look for a short to ground. also still could be alt.....good luck with the problem to get fixed.