I'm having a issue on my 2005 dodge 2500 5.9. The voltage keeps shooting up and down between 13 volts and 17 volts. I changed the alternator, changed the batteries changed the terminals and it still does the same thing. No Fuses were blown. At one point it completely drained the battery's causing the truck to shut off. This was the reason I purchased the new batteries thinking they were defective. The problem stopped for a few days then it returned. It has something to do with the drivers side "main" battery because i disconnect the passenger battery and it still continues to surge. It drives but feels as if it is struggling when you give it throttle. I have exhausted all my efforts I need some help. Any ideas of the cause? Thanks.

 

Clean all your grounds and connections pull the ecm harness off and clean and check for corrosion. The ecm controls the charging system also the PCS "fuse Block" can cause this. If it still does it take it to the dealer for diagnosis they can scan it all!

 

I'm going to do this tomorrow as well as change the alternator again to see if I got a defective one. How do I check the Fuse block? I heard you can place an external regulator if the ECM is giving out a bad charge signal. I'm going to try this out. Thanks again man I really appreciate it I have a hunting trip on Friday so I'm cutting it close.