Auto body repair & detailing: Battery, gm product, pontiac grand am

Question
I have a 93 Pontiac Grand AM, recently I had a problem with my battery and took it to a shop to check it. They told me it needed a new alternator so I had it replaced which cost me 240 bucks. Now two days later this evening at night the ABS light comes on and as I start slowing down the car shuts off. In order to keep the car running I have to excelerate the car.  

Answer
I would take the car back to the shop and tell them that it ran fine before they touched it. They might have put a bad one on it. for that price it should have been an original GM product not a used or rebuilt one. While its there have them put it on a scope, hopefully the have one unless they are backyard mec.

                let me know how you make out if this dousnt help I investigate further
                                     Brian