2000 Infinity quit on the road - the dashboard went black and the engine stopped.

Mechanic changed the battery and tells me it would be fine. I disconnected the battery on a running engine and it dies. Should the car continue to run when battery is disconnected?

 

The engine needs power for the spark

 

but isnt the power comming from the alternator..? once the enine is running..?

 

A little of both, more the alternator. You keep unplugging the battery while the engine is running and your alternator WILL go.

 

If you disconect the battery while the car is running, the engine should die!

 

On my old 98 SE, my brother in law dented the rear. When I got it repaired, the shop did not tighten the battery which I found out when I hit a speed bump. The cable lost its connection and the car died. After I found the problem and tightened the battery cables, the car started right up.

 

HOW IS THIS POSSIBLE???
One time the alternator in my girls car died so what we did was drive another car behiind her, put a fresh batt. in her car when her car died just changed the batt with the good car's batt while still running and never died, we kept doing this until we got home.

 

Most cars need a battery to run.
Your dashboard going off and then shutting off is a common symptom of your alternator going bad. You might want to check it.

 

The car should keep running if the alt is good when you disconnect the batt.
I have worked for Nissan for 15 years and sometimes I undo the batt when the car is running(not a good idea but time is money) and they still run.

 

SOME CARS- YES. OUR CARS- NO!!!

some get their juice from the alternator (mostly older cars), others get it from the battery (mostly newer cars).