Is it a bad alternator?

[Vlad]

Periodically, not often but on my dashboard pops up truck ABS and triangle with combination over voltage 16 volts or more with buzzing. Cummins inside doesn’t shows any fault codes. After couple minutes it disappeared

[smorgan87]

Use a multimeter and check ur voltage. Volt regulator may be bad in the alternator.

[Rawze]

what kind of truck? engine? some history?

Jhave you checked the voltage to see if it is going that high?. 16+ volts can fry some very expensive things like ECM and cab controllers.

[Vlad]

International Prostar 2011. CM871. It’s appear for 1-2 minuets some times and after disappears

[Rawze]

may be a loose connection to the alternator voltage sense wire?.

[Vlad]

I replaced alternator (remanuf 235$ + labor) Now everything is OK!

[cheeseman6697]

Alternators generally don't go bad. Its usually the Voltage regulator. The Alt on my trk is 1200.00. put a new 18$ voltage regulator on it, problem solved