It is therefore possible to jump start a vehicle with a 12 v electrical system using only one of the two batteries.
Jump start 24 volt system.
Some 24 volt systems use 24 volt batteries while others wire two 12 volt batteries in series.
The same result will be achieved by connecting the red jumper cable to the positive terminal marked a and the black jumper cable to the earth terminal or chassis of the bus.
In either case if a vehicle with a 24 volt battery needs a jump start it can be a headache.
Jump starting a 24volt truck from another 24volt truck.
Since the power of a 24 volt system will overload a 12 volt one in another vehicle you will need another 24 volt battery to provide the power.
Put the 24 volt truck in neutral and start it following the normal procedure.
You don t because of the voltage differences between sources to jump start you must have the same voltage at destination and source the source may be higher than the destination but destination.
Connect a second jump lead between the negative terminal and the engine block or other ground connection in the 24 volt truck.
Trucks usually have a 24 v supply using two 12 v automotive batteries in series.
Once the bus starts quickly remove the jumper cables so that the bus alternator can take over the charging of the 24 volt system.
Connect a jump lead from the positive terminal to the positive terminal on the 24 volt truck battery.
Since the power of a 24 volt system will overload a 12 volt one in another vehicle you will need another 24 volt battery to provide the power.