#24 volt alternator charging system how to#

If the car is running and you are seeing 12.2 to 12.4 volts, (that’s less than 12.6) that usually means the alternator is doing nothing. When your engine is running, the ignition system is drawing power from the battery. So, a fully charged battery in your car that’s neither charging nor discharging will be around 12.6 volts. A fully charged 12 volt battery should yield 12.6 about volts. The meter should be reading in the 13 volt range to the 14 volt range. Two wires.īecause your alternator is connected directly to your battery, your meter will be reading battery voltage. Connect the black lead from your meter to a good ground. Connect (piggy-back) the red lead of your meter to the big lead on the alternator where the current comes out. If your meter automatically sets its own range, be sure it’s on DC and let it work on its own. If your meter has buttons to set the voltage range, again 20 volts DC. If your meter has a dial to set a voltage range, set it to 20 volts DC. The wires and cables are still connected. Maybe we had a dead battery this morning. We suspect our charging system has a problem. So, all we really need to know is this is my alternator faulty or not? We can determine that with a volt meter. With the cost of labor, and the difficulties of finding original internal replacement parts for the original alternators, it’s usually faster, and less costly, to simply replace a defective alternator. You can test virtually everything you need to test on this with a volt meter.Ī person might sound surprised and ask, ‘How am I going to diagnose and service something like this without a box of tools and test equipment?’ The question is valid, but it overlooks the realities of our modern world. That relearning leads to a pleasant surprise.

#24 volt alternator charging system how to#

This is a better package, but it means we need to relearn how to test our charging system. Alternators do, and it also lives inside the alternator.

Generators never had a part called a diode bank (or a rectifier).

The voltage regulator lives inside the alternator. Looking at the differences between generators and alternators, we find the stator windings and the armature windings have swapped roles. Alternators were less expensive to build than generators, more effective at low RPM’s than generators, smaller than generators, lighter than generators, required less maintenance than generators, and came with their own voltage regulator. In the 1960’s, our Classic British cars started coming with alternators. This video shows how to check for correct voltage at the alternator and diagnose if a diode has gone bad internally.