DISCRIMINATION!!! PREJUDICE!!! ummm.... I guess they think that since we have half the cylinders, that we only deserve half the attention. therefore, when they mess up, and you bring it back in, you get the other half of the attention they should have given you to begin with.
even better just pickup a 2.5 turbo engine with computer and wirrring harness and drop it in , add an intercooler, and read the late Gus Mahon webpages and you could have really serious fun !
This is what you do [after they fix this problem of course]: Take a LONG steel cable, loop it around everyone that works there's driveshaft/cv joint/rear axle [whichever one is available or more costly] and make sure they have enough slack to replicate that scene from American Grafitti.
I'm going to assume that you've already checked the voltage of all the wires, and cleaned the contacts, so the next step would be to have the alternator checked while it's on the car. If you have a local Advance or [heaven forbid] Autozone, have them use their mobile machine to check the alternator. Since it bench tested fine, if it doesn't have the same satisfactory results while it's on the car, then you'll know where to start on your wiring hunt.
As far as the battery goes, what is the:
CCA: Age*: Brand: X year warranty: Price paid*:
*If you know or bought it that is.
When i worked at Advance, we would have people who thought they knew what they were talking about, try to buy a battery that was 'inexpensive'. Even though we weren't trying to oversell them a battery that they didn't really need, they still went after the cheap one because it saved them money 'right now'. They wouldn't listen to us when we told them about the minimum required CCA for the vehicle [which i always recommend you go at least 100CCA more than the factory setting].
Grounding straps can be a problem. lol. once you have the alternator back on, have it tested on the car. If it tests good off, but bad on, that means you've got a wire problem. I know that's an obvious statement, but sometimes it helps to have it said out loud.