Charging system – Alternator to the battery lead
The purpose of the lead from the alternator to the battery is to supply the power from the alternator to the battery. This charging power is good for at least 5 to 10 years. After this time the cable may become hardened or the connections may be creating a resistance. All this means is a power voltage drop between the alternator and the positive battery terminal.
THINGS TO LOOK FOR
The best way to check the power from the alternator to the battery is to get a Multimeter. The first check is to check the power across the battery, the positive and negative pole, and then compare that to the power from the positive terminal at the rear of the alternator to the power across the battery terminals. If the power is showing a difference then this is an indication of a voltage drop or a bad cable connection to the alternator.
IS IT EXPENSIVE TO REPAIR?
It is an inexpensive repair. Purchase some heavy duty 15-20 amp cable and make sure that it is long enough so that when the engine revs the cable still has plenty of slack. So make sure when fitting this cable that it doesn’t interfere with any other component as if it does wear against any other component it may short out the whole electrical system. Make sure the terminals are soldered on each end and connect the cable from the positive alternator terminal to the positive battery terminal and measure the volts across the battery and the negative battery pole to the positive alternator terminal and they should be the same.