I recently bought an 1991 XR2 built 6/91 with only 34,000 miles. Before I bought it, the prior owner had a new alternator installed. Within a few weeks in my hands the alternator belt broke, the replacement belt never stopped slipping. I did some research and found that 1991s had 85 amp Bosch alternators. The one installed on my XR2 was clearly the Mitsu, and worse, with a too-wide pulley. I found a rebuilt 1991 Bosch/AC Delco unit, with correct pulley, and asked my garage to put it in. As we discovered, Bosch & Mitsu connectors are different. The mechanic said I had to use a Mitsu; could not just change connectors. I needed to get the car on the road, and with no new Mitsu with the correct pulley available I had a wider belt (Gates 7350) installed. That mostly works. Slips sometimes only when starting. Now time for a permanent fix.
Was my 1991 built with the Bosch unit or were some built with Mitsu? Was the mechanic wrong, can I just swap connectors and use the Bosch? Or should I get a proper pulley for the Mitsu?