Poor Quality, Part 5, Delco 22SI Truck Alternator

Last week a customer came in, in trouble as he was broke down on the road and just passing through.  He had this 130 Amp Delco alternator that had quit charging and he tried to take it apart to see if he could fix it, but couldn't get it together correctly and broke one of the brushes.

Generally, I would fault him for taking it apart without knowing much about them and causing damage, but there were several other issues with this unit that were not his fault!  This was a rebuild that he bought at a parts store in Chicago and he only got a thousand miles out of it before it failed.  The two major issues were that the ground screws that held the rectifier in were stripped when installed, causing the rectifier to get loose and arcing to the ground, blowing a couple of the diodes in it.  The other issue was that the rebuilder installed the wrong brush holder assembly causing miss-alignment of the brushes with the rotor.  The brush holder mounting bosses inside differ from the Delco 21SI alternator which looks almost identical on the outside.

I ended up putting a couple of heli-coils in the bolt holes, replaced the rectifier and put the correct brush holder in the unit to get him back on the road.  This was a needless repair and would have not been necessary if only the rebuilder had done his job right!  The stress of this repair was compounded by the fact that he stood right there and that I had trouble with the unit having to assemble and take it apart several times before I finally got it fixed!  If I had any idea who the original rebuilder was I would post his name and company here and warn everyone to stay away from him!!!