[pyramids111]

Can someone please test this on an e38:
Turn the car on and remove the negative cable form the battery. Does the car still keep running, or does it shut off?
People keep telling me that the car should keep running indefinitely even without the negative connected, but my e38 shuts off after like 15 seconds. Please let me know. It is important!
Thanks!

 

[slidebabyslide]

your alternator is probably going out if not already gone.

 

[bobwatt]

pyramids111, what are you trying to prove? Taking the terminal off the battery if the alternator is charging will cause the voltage to rise and this could blow some of the many electronic components not designed to handle higher voltages, especially if you rev up the motor. Rather use a multimeter/ voltmeter to solve your problem.