Q. I have a 1991 Chevrolet K2500 pickup with 5.7-liter engine. I just put in my ninth CS 130 alternator since I bought this truck in 1995. They did not all have the same failures. Five had diode problems and three failed with bearings going out (two caught fire) and one had the pulley fall off.
I know this is a fairly common problem because of the Internet chat groups. I need a decent way to fix this, as I pull a 26-foot Innsbruck trailer and use the truck to keep the trailer batteries charged. I now travel with two spare alternators.
— C.V., Claremore, Oklahoma
A. You may hold an alternator record there! The bearing failures might be caused by excessive sand and grit or a belt that’s running too tight. The diode failures could be caused by a combination of high heat and heavy current loads. Sometimes, weak cells in the batteries will cause the alternator to work extra hard to charge faulty batteries, so check for this.
There’s a new Mean Green high-output, heavy-duty alternator from M.G. Industries, (724-532-3090, mean-green.com) that’s designed as a direct replacement. This may be your solution. — K.F.
Ken Freund’s more than three decades of auto-repair experience and 20-plus years of RVing
helped him author numerous books and articles on vehicle repair. In addition to RV Clinic
and Performance, he writes the Powertrain column in MotorHome magazine. Ken has been a
California Automotive VO-Tech and Smog-Test Program Instructor and an ASE-certified Master