I have a question about the electrical system on the 2018 Silverado 6.0L.
This is a new truck with around 800 miles on it. Yesterday I made a round trip run of about 500 miles. My question surrounds the readings I got on the truck's volt meter, and on the scan gauge 2.
When I left on the trip I was still abiding by Chevy's break-in procedure. About the first 200 miles I was not exceeding 55mph, and varying my speed. Once the break-in mileage was reached I ran more at posted speeds All that time and since we purchased the vehicle, the volt meter and the scan gauge read a voltage of about 14.3-14.7 volts(I have a scan gauge plugged into the OBD). It would be higher after start up as the alternator was outputting more to make up for starting, and as it ran it would settle into its 14.3 range. On this trip it stayed in this range until I started home. About 60 miles in on the return home, the voltage dropped to 12.3. It would stay at 12.3 volts and the increase to 14.5, and then back to 12.3. Since this looked like a potential problem with the alternator I called a local Chevy dealership. I was told this was normal, and not to sweat it unless the idiot light came on. The tech said that the ECM was needing more voltage due to needs of the entire system. I turned everything off that I could after learning this and it had zero effect on the issue. So, on the way home the voltage stayed at 12.3-12.4 most of 180 or so miles. Only occasionally and momentarily going up to 14.5 then right back down to 12.3. When I parked it in the garage, it was at 12.3 volts.
I'm curious if any of you have seen this? What is going on with the system that this occurs? Is this really normal, or do I have a budding problem that will leave me walking? Are there any GM techs on the site that can explain this?
The owners manual talks about this as an issue, but not to any degree that satisfies me.
Thanks guys!
This is a new truck with around 800 miles on it. Yesterday I made a round trip run of about 500 miles. My question surrounds the readings I got on the truck's volt meter, and on the scan gauge 2.
When I left on the trip I was still abiding by Chevy's break-in procedure. About the first 200 miles I was not exceeding 55mph, and varying my speed. Once the break-in mileage was reached I ran more at posted speeds All that time and since we purchased the vehicle, the volt meter and the scan gauge read a voltage of about 14.3-14.7 volts(I have a scan gauge plugged into the OBD). It would be higher after start up as the alternator was outputting more to make up for starting, and as it ran it would settle into its 14.3 range. On this trip it stayed in this range until I started home. About 60 miles in on the return home, the voltage dropped to 12.3. It would stay at 12.3 volts and the increase to 14.5, and then back to 12.3. Since this looked like a potential problem with the alternator I called a local Chevy dealership. I was told this was normal, and not to sweat it unless the idiot light came on. The tech said that the ECM was needing more voltage due to needs of the entire system. I turned everything off that I could after learning this and it had zero effect on the issue. So, on the way home the voltage stayed at 12.3-12.4 most of 180 or so miles. Only occasionally and momentarily going up to 14.5 then right back down to 12.3. When I parked it in the garage, it was at 12.3 volts.
I'm curious if any of you have seen this? What is going on with the system that this occurs? Is this really normal, or do I have a budding problem that will leave me walking? Are there any GM techs on the site that can explain this?
The owners manual talks about this as an issue, but not to any degree that satisfies me.
Thanks guys!
