Alternator problems

Ok this all began last summer when I wanted to replace my alternator and battery for winter. I didn't want to end up stranded in the middle of nowhere in the blistering cold because of an old battery or alternator, so I bought both. The alternator was a refurbished 105 amp alternator and the battery is 700 amps, 850 amps cold. All was fine and dandy for about 2 weeks after the installation of both of these devices but then my alternator problems all began. The alternator spiked out at 18 volts so I took it back and had it replaced with another refurbished unit(tested right in front of me). Installed the 2nd alternator, started the car and it instantaneously spiked to about 20 volts. So I brought the alternator back to the store and recieved yet another refurbished alternator. Installed it at home and it worked fine for about 3 months - till today. No spike in voltage this time, just a sudden stop in power production. I go back and get the lecture of how my car must be messed up and a refusal to sell anymore alternators to me (money back).
By now I am wishing to god I had not got the idea in my head to replace that already working alternator. SO I take the mans advice and check between the negative terminal of my battery and negative wire for shorts. Sure enough the power kicks on for the computer and off the voltage draw goes (no shorts). I grabbed a volt meter and checked the resistance between where the positive battery terminal connects to the battery and the power line that connects to the alternator. A resistance reading of 0...... this has me thinking nothing is wrong with this wire. So I head off to another store where they tell me they have ran into refurbished alternator stock line failures. (BAD REFURBISHED ALTERNATORS) So not knowing if I am getting a bad refurbished alternator or not I hesitantly buy another refurbished alternator. Install it here at home and drive around fine for about an hour. Here it is 10 pm and I had to retension my belt..... do that, restart the car and the alternator has completely crapped out.
I don't know what to do anymore - the best suggestion I have recieved is to buy a new alternator, not a refurbished one. I can't stand the words of that guy in my head saying your car must be messed up when I had drove on an refurbished alternator for 2 months with no problems... Checked for shorts.... none, resistance in the charging system wires for the power output of the alternator is 0. Now I sit with my 4th burnt out refurbished alternator.

Any suggestions?

I don't know about the GTP's, but my dad had a blazer that ate alternators like that too, I think he put two new ones in it.

I don't know, I would sugjest trying a new one and see if that fixes it. And next time you get a working one, don't replace it.

Save your money on refurbs and go to a wrecking yard and get an OEM alternator. It sounds like the refurbs are not being adequately redone or they are using cheap diodes. If the OEM from the wrecking yard works then you will know how to procede from this point forward. If you still have problems then there may be a problem in the charging circuit of your car.