b2300 alternator issues

we have a 96 mazda b2300 that randomly died in the middle of driving. we took it to oreily's and tested both the battery and alternator. alternator was apparently putting out only 11 volts of power but the battery was seeminly fine. we installed the new alternator, ran the engine, but the charge was not holding. we got it jumped and ran it back to oreily's only to find out this alternator was putting out 8 volts. they said ther could be a wiring problem but we don't know where to begin. any clues? any answers? feel free to call or message. thanks. :banghead: