Cummins 8.3 alternator charging, digital displays not reading

[Jon Tisdale]

Hi guys my port side 8.3 480 computer doesn’t read the alternator output voltage. How are the engine computers wired ? Brand new alternator from Cummins reads 14.4 at the positive post on the alternator, however when it’s reading that at the alternator, the port side display only reads 12.1. I had a battery isolator that was bad and removed it completely and first trip out after that it read 13.6-14 the whole trip. Now it only reads 11-8-12 while running. Any guesses? Thanks guys

Topic

[Tony Athens]

The only voltage you should be reading is “BATTERY TERMINAL VOLTAGE” if you want to troubleshoot what is going on……………………………………… Until you do that, IMO, both you, me, or any tech are just guessing where your issues really are.

Installing Digital Volt Meters (DVM) on Your Boat

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