I have an 'O6 Dodge Cummins. The battery needle jumps 8-16 amps. What do I do with it?
The first thing you have to realize is that, a lot of times, those gauges are built on those dashes are reasonably cheap and not all that accurate.
The first thing I would advise doing would be to have a mechanic hook up his gauges and see if the battery is okay. See if that the alternator is charging right or not. Because it could be that those that gauges just aren't accurate.
They are highly inaccurate gauges to begin with. But if it is accurate, that would mean that you charging is oscillating too much. It would generally mean that either you have a wiring short somewhere that is draining a bunch of power or you have a problem with your voltage regulator which is built in the alternator. So, have the alternator load tested too, to see if that has got a problem in it. If it's not that, then it has got a wiring problem somewhere that's making them jump up and down.
If you want to have this diagnosed for you by a professional, a certified technician from YourMechanic can come to your home or office to inspect your battery and see if there are any services that are needed.
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