I told Robert to check for a current drain with thew car off. Easy to do with a multimeter.
Disconnect the -ve form the baterry and put the multimeter inline with eh batter and ground wire to close the circuit. Of course switch the multimeter to the "current" function. There should be a VERY slight current drain from the PATS light and that's it. So long as the dorrs are closed, light off, and all that jazz. If you are seeing a few amps getting pulled then you have something shorting out causing a drain on the system at all times.
The belt tension is a BS problem. There's almost no chance that he is getting so much belt slip that he is losing voltage - I don't buy that for one second. The thing would be squealing like a pig if that was the case.
Also for him to have 5 bad alternators in a row is pretty high odds.
Other thing you wanna check for is the fuse and contacts for the voltage regulator for the alternator. Make sure the fuse isn't blown or had corrosion it or the connections, that would cause issues like your seeing.
Personally I think either he has some bad grounds, shorts in the system or bad +ve connections. Also have your battery checked in the off chance it has a bad cell.
One thing I would try is unhooking your amp/cap completely to see if they are possible bad causing a drain. Work your way through each electrical accessory you have, unhooking each one, one at a time. It's the only way to get down to the bottom of this debacle.
