alternator troubles please?

You don't "get ripped" at a shop. You just have to pay the mechanic for fixing your car. Did you check the fusible links yet to see if you blew one from jumping the battery the wrong way? That's what most people that don't have a clue do. They make things worse and more costly. You see...your paranoia should be about YOU ripping yourself off because you don't know what you're doing guessing and throwing parts at the car, not thinking you're getting ripped off by a professional that diagnoses things before coming to a conclusion about what needs to be done. I'll bet the old battery was bad and you jumped the old battery and fried the fusible link. When you put the new battery in it wasn't being charged because the fusible link was blown and you just drained it driving. You probably didn't even need an alternator! DUH Feel better now?!

Many chain parts stores will test it for free so just drive there. They will at least let you know if the alternator is working.

Two suspects.

1. Like M said a drain in the car is killing the battery, if disconnecting it for the night helps that is the problem.

2. The fuse link was blown like thebax2006 said. Someone or you will need to check the large power lug on the alternator to see if it has the same voltage as the battery if not the fuse has been blown. This is not too expensive to.

If performing #1 doesn't help replace the fuse link.

Batteries don't usually get fried. With the car running, there should be around 14.4 volts on the battery. This shows the charging system is working. That means alternator. If there is 13 volts or 12 volts, the charging system is not working. But there's more to the charging system than the alternator.

There also is a possibility of a hidden load on the battery, when the car is parked. Like a glovebox light, trunk light, engine compartment light that's stuck on, or a power antenna that is stuck on.

READ CAREFULLY HERE! WALMART batteries are MOSTLY JUNK! You're BEST OFF with REAL JAPANESE batteries checked over at JUNK YARDS! NEW ALTERNATORS are many times just a REBUILD by a cheap company! THE FACTORY uses DENSO alternators! Get an EXCHANGE one from ANY JAPANESE car dealership as they ALL use the SAME ELECTRICAL SUPPLIERS! DENSO and BOSCH rule most of the WORLD!~ IF your battery does NOT have FILL CAPS< it is a VERY CHEAP ONE! ALl REAL cars from EUROPE an JAPANESE use REAL batteries with FILL CAPS on them! WALMART sells mostly JUNK auto parts and your ALTERNATOR may STILL be defective here! POWER WASH ENGINE with GUNK ORANGE improve the WIRING HARNESS and to keep the BELTS clean and free of LEAKING OILS and FLUIDS under the hood! ANY AUTO ZONE can test your START and CHARGE system for FREE with a testing device ON THE CAR! IT SI VERY COMMON for the BATTERY, ALTERNATOR and VOLTAGE REGULATOR to all fail at the SAME TIME! You cannot go wrong with a DEKA battery either or a genuine BOSCH or DENSO rebuilt ALTERNATOR! OTher rebuilders use CHEAPER KOREAN and CHINESE parts in them! GOOD LUCK!!

buy a cheap voltage meter, use it to determine if your alternator is working, You could have a voltage draw when the car is off draining your battery. I will speculate if you get a jump and it runs and you can use the lights and it goes just fine until you shut it off the charging system is working. If the car stalls the charging system is not working. If you shut it off and when you come to start it the battery is dead you have a draw while the car is off.

Make sure the alternator is properly charging(have it tested). Sometimes the belt slips or the resistor/brushes inside of the alternator wear down and doesn't properly charge.

Also make sure the doors are shut properly at night.

There is something that is still on when you leave the car at night. Make sure there are no lights on or chargers in the lighter socket, doors closed, trunk, etc.