AutoZone alternator warning
We're towing our 27B with a 2002 F-250 SuperDuty with a PowerStroke 7.3 diesel. Last year in Colorado the factory alternator failed. I got a replacement from AutoZone for about $200. I swapped it out in the parking lot of the auto parts store in about 30 min. and turned my old one in for the core charge.
About a thousand miles or so later, in Texas, was driving from Cowtown RV in Aledo into Ft. Worth when the gauges started acting crazy on the truck. They would all go completely dead, or peg all the way to the right. Radio didn't work. Diesel ran fine, of course, but no speedo or other instrumentation.
After going through all the usual head scratching I finally put a DVOM on the alternator output, and found that even with the truck at idle it was outputting around 18 volts. At higher rpms I was seeing 20 volts. I took the alternator to the nearest auto zone in Westford and explained that the voltage regulator had gone belly up. They tested the alternator and agreed and replaced it on the spot.
The truck was stored for the winter, and then we drove it back to Colorado for the season. On the way to Montana we had the same symptoms with the gauges. Knew what to look for, and this alternator was putting out over 20 volts and my batteries were boiling. Literally. No AutoZone in Pinedale Wyoming, so I bought a remanufactured alternator from NAPA. And noticed that there was a tag on it that listed the outputs at various rpms, etc. Looked at the AutoZone alternator that had just failed and the only info on that was that it was remanufactured in Mexico.
It's now two months and about 4,000 miles later and the NAPA alternator is doing fine. I took the second Autozone alternator back to the original Ft, Collin store where I bought the first one and they were very nice about what I wanted to do about it. I took a full refund.