Bad Alternator?

94 XE with about 115,000 on the odo. We recently replaced the alternator, using my mechanic and part bought locally (reman). Now the alternator light flashes intermittently. When bench tested, the parts store tells me the unit is OK. My mechanic says it's an intermittent problem and that the unit is defective. Who's right?

if it sometimes happens and sometimes doesnt, then it is probably a bad alt.
could be charging system wiring or loose grounds also...

take it to an alt. rebuild shop to have it tested. i wouldnt trust a parts store with a correct anything
shit they get my parts wrong half the time.