I am having issues with my 92 deville i suspected the alternator and took it to an auto parts store
They tested the alternator and passed all tests
They only run a quick test less than a minute,
Now i do nit know what to do?
The symptoms are the following,
While engine running at idle with no lights or usage of any electrical component,
Voltage reads 13.6 volts,
But as soon i use ANY electrical item such as the power widow or turning on the headlamps or steeping on to the brake pedal
My voltage drops to 12.2 volts and the cars starts running realy rough i can not drive the car because there is lack of power and then it starts
Backfiring,the wird thing is my dashboard runs good no engine check light or alternator light, i am running in to wall, can anyone help me?
P L E A S E