Quote Originally Posted by deedee View Post
another tet is turn your engine on,run on idle and disconnect the battery positive line.if the car dies..your alternator just conked out.(it should stay running even without the battery connected.
this used to be ok for old school cars without sensitive electronic components

modern cars, those with ECU's, have sensitive electronic components, the ECU itself and sensors, aircon controls, alarm system, stereo, etc. can be damaged with this procedure ...

[SIZE="4"]removing the battery terminal/s and letting the alternator supply power alone can produce transient voltages up to 80 volts on the system ... and if you happen to have a defective/shorted regulator (inside the alternator) or a shorted diode, you're asking for a disaster![/SIZE]

[SIZE="6"]you were warned! don't ever let anybody do this procedure to your modern cars![/SIZE]

consider yourself very lucky if your car survived this dangerous test!