voltage regulator

[Dean Ansaldo]

where is the voltage regulator located 2006 5.9 cummins , first 5 minutes of start up volt guage bounces around lights ho bright n dim after it settles it reads about 14.8

 

[HemiLonestar]

PCM controls voltage, 14.8 seems a bit high

 

[crash68]

If this voltage fluctuation has started since it has been getting colder, it possible the grid heater is causing the voltage issue. You may want to have your batteries test also, one of them may be going bad(if that's the case you have to replace both batteries).

 

[Dean Ansaldo]

it was doing it it warm weather also , batteries are only a year old , put a scan tool on it the other day and high voltage code came up

 

[Dean Ansaldo]

it was doing it when it was warm out also, batteries only a year old,put a scan tool on it the other day code came up high voltage