A neighbor's truck had a dead battery so we jumped it to get it started. But as soon as we disconnected the jumper cables after getting it started the truck died. We next jumped it and then shut down the other vehicle so the Rover was running from the other vehicle's battery long enough for us to hook up my battery charger and run the alternator test built into my charger. It showed an alternator fault. Looks like he needs a new alternator at least, if not also a new battery.

But back to the thread title - it makes sense that the Rover should shut down if the alternator is not working and the battery is also dead, but does this indicate any other problem?

 

Replace your alternator, have the charging system tested under full load. The voltage must be between 13.6 and 14.4 volts, then you may still need to replace the battery.

 

Everything on the truck runs off of electricity, with no electricity in the battery and none coming from the alternator there is none for the truck to run on, no electricity no fuel pump, no fuel pump no fuel to the engine, no electricity means no spark for the spark plugs...everything runs on electricity.
I bet your battery is good, replace the alternator, charge battery over night, have battery tested, replace if needed.

 

First - this is not a good idea to run a truck on jumper cables.
Why?

If you remove the cables and the battery is open - no taking a load - the voltage could in theory go to infinity and blow out the diodes in the alternator, the regulator and the engine control and trans control computers.

2nd -
Always replace the battery. Walmart $110 or so.

Then the truck will start.

IF the new battery runs down, then replace the alternator.
That's all there is to it.

 

Can be several problems. One is battery has internal short, and battery cables can have plastic melt off them and dribble down the fender. Other is alternator on bad battery truck is so weak it can't supply running power for truck. The jump boost only lasts a few seconds or minutes if alternator is not putting out. Alternators are three phase AC to DC devices, so one diode takes out 33%, two diodes can take out 66% of capacity, etc. You could also have wire loose to alternator (exciter side or main output side).