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1999 Dodge Ram 3500 with 5.9 Cummins. When the truck is running, any lights that are on, dash, interior, exterior will hyper flash. I have even added extra grounds to the batteries, voltage regulator, and alternator. The turn signal bulbs operate as they should, as do high and low beam . Voltage runs a bit high, but within parameters. Any diag help is appreciated.
you mean the lights flicker? like the headlights and dash lights? sounds like a bad alternator. you could check the ac ripple in the system. or id just try disconnecting the alternator connector and see if it quits whileits running
Thanks for the reply. I checked for voltage drop and AC ripple, all lower than max allowed. I have been instructed to not disconnect the alternator when running as it could damage computers.
Last edit: 5 years 1 month ago by Chuck69. Reason: reply to test suggestions.
As Cherly's answer it also sounds like a bad alternator to me but checking the the main battery connections at the alternator would also be on the cards. It is the kind of issue where an oscilloscope is handy but without one it is really down to visual inspection and as a last resort parts swapping.
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