[chalkyh]

Do a volt drop between the alternator + and the battery +, anything greater that a 0.5 volt reading on the meter is a concern - there's a resistance in the wire. Also battery - to engine block, same test; but checking continuity of the main batt - to engine earth strap. Anything greater than 0.5 volt on the meter again is showing a resistance in that ground strap. Also try engine block to alternator body, again looking for less than 0.5 volts on the meter. That could be paint between the alternator body and the fixing brackets.

You're missing near 2v on the system somewhere between the alternator (14.2v) and battery (12.4v), both should be about the same. Remember that can be on the + cabling side or the ground side! A battery ideally sits at 12.7 volts or so static and fully charged (without a surface charge) and needs another 1.5v or so to successfully charge.