On a recent family trip a few miles from our destination, all my vehicle's dash controls went out, then reappeared with a charging system error indicator.
Everything seemed fine - I watched battery gauge and hoped I'd make it. When I got to the destination, I stopped and restarted the engine, and everything looked fine, and the charging system indicator went back to normal.
I noticed afterward that the "Engine Hours", which had been getting close to 10,000, was now in single digits. No other internal counters were reset.
I wondered if it was an overflow condition, but it appears more mundane - many vehicle owners report seemingly random resets. The surprising thing seems to be that it hadn't reset before getting close to 10,000 hours!
30 odometer miles per engine hour seems about average (to one significant digit - varies with proportion of highway vs city vs idle hours). That would suggest all your 20+ year old cars are under about 120K miles? Or they have a very high mix of freeway miles. Either way, they're not likely getting the average 10-15k miles per year.
Conversely, that rough evaluation is making me question whether my recollection of nearing 10K hours was correct - the vehicle is under 200K miles, which would suggest <20mph average.
Everything seemed fine - I watched battery gauge and hoped I'd make it. When I got to the destination, I stopped and restarted the engine, and everything looked fine, and the charging system indicator went back to normal.
I noticed afterward that the "Engine Hours", which had been getting close to 10,000, was now in single digits. No other internal counters were reset.
I wondered if it was an overflow condition, but it appears more mundane - many vehicle owners report seemingly random resets. The surprising thing seems to be that it hadn't reset before getting close to 10,000 hours!