Looking for Help!! Voltage issues 2016 International.

I have no idea where to start. Sounds like the shop has the"keep throwing parts at it" policy. Is this your truck or a company truck? If it is a company truck, let them use the above method. If you own the truck..... Find a new shop.

 

Check your grounds, all of them.

many shops will not check the grounds or clean contact points because they don’t understand how the charging system works.

 

I agree, a bad ground will do crazy things. I wouldn't trust a dash gauge as being gospel, but clearly a problem. Does the alternator get hot to the touch? I drove a Mack once, went through 3 alternators in a month, and everytime they were so hot, you couldn't touch them. A new ground to the frame solved the problem. My WS did the same thing, erratic voltage and a new ground fixed it.

 

I agree with the grounds, but you definitely wouldn't be the first person to get a bad alternator from the parts department. Many times no one looks at the part that was just replaced. Happened to a buddy a couple months ago and had to do two alternator swaps on the job site that day.

Anything smelling when this happens?

 

I agree with the grounds check, but, the ECM does voltage regulation now, at least on most vehicles. The sense wire back to the ecm could be bad or the ecm could have issues.

Can we just go back to the good old days, when vehicles had and alternator, a rectifier, and a regulator, all separate?

 

Wrenched on all of my cars and motorcycles my whole life. I miss the ease of troubleshooting and repairing the old stuff.

 

Did you solve your voltage issue ?