2016 GMC Denali low voltage problem

[mbubbaca]

Not asking if it will tow,what it will tow or the like. Asking if any AF members have had a problem with low voltage causing issues with the GPS function. I have an intermittent issues with GPS not locking in, just scanning around the map, random destinations with miles to it displayed for a second or two and then moving on. I finally got into the GMC dealer with the problem actually happening. They ran diagnostics and came up with low voltage codes ( no I don’t have the code numbers). There is a bulletin from GM about low voltage issues being solved by replacing the fuse block. I’m out of warranty so it would be on my dime. Anyone have the same issue? How was it solved? Since there is a service bulletin, there should be someone with experience in this group.

[Airstreamer67]

The first thing I'd do is buy a voltage gauge to see exactly what is going on with the electric system when on the road.

A problem with the fuse box implies that the fuse box is somehow reducing voltage on at least some circuits. Unless this is a safety issue relating to fire or other problems, and unless you are seeing problems with other appliances on the truck, you might be able to work around the problem without the expense of changing out the fuse box.

One idea is that if nothing else is being affected but the GPS, it wouldn't cost more than a few bucks to run a dedicated 12vdc line from the battery to service just the GPS.

If the whole electric system is seeing low voltage, it's curious you haven't seen other problems. If the alternator or voltage regulator are the culprits, you'd think the battery would be having problems.

Get the voltmeter to see what's up. A dealer can be less than helpful sometimes.