Is 14.6 volts too high

13.8 is the norm. Could be a bad battery that won't charge.

 

Past 3 trucks I've been in all 3 generated 14.1v. As long as your system is between 13v and 15v you're system is within normal limits

 

14.6 is a little high but not too high to be concerned. If it continues to climb, it will overcharge the batteries and boil them out, basically ruining them. It’s accompanied by a sulfur smell. The voltage regulator may be going out, just keep an eye on it.

 

Tap on the alternator. May have dust built up on brushes.

 

I'm at 14.2 on my Cascadia . I had new batteries out in and they ran at 14.3 to 14.5 for a day .

 

I think you may be overcharging the batteries. I went through 3 sets of batteries on a new Pete because the factory shipped our trucks with a defect. It charged 14.6 constantly. Eventually, our Dealer fixed it free of charge.

 

I had this on my 2016. On the PNDB module on the firewall there is a fuse “Alt Remote Sense” , it is probably blown. Only a five amp fuse.
Mine was blown , alternator was at 14.6, went back down to 14.0 after that.

 

It’s raining right now and my 2015 cascadia shows 14.6. May catch fire and burn to ground if I’m lucky