Replaced Battery and Alternator car runs for a week and then is completely dead and will not start

In all probability you have a parasitic drain somewhere in the electrical system. Check the easy things first. With a volt meter make sure the alternator is putting out the proper voltage when the car is running. They have been known to be bad right out of the box. A wiring diagram and a knowledgeable person with a meter is the next step.

Thanks OJ. My mechanic is doing the parasitic test, but has not found the problem yet. Going one at a time.

Parasitic tests have been done, but still the same issue. Started all week-end, but when I went out to start it this morning it just made a clicking sound. My mechanic has just thrown up his hands. He is thinking the ABS system is not communicating with the computer???? Have no idea what that means.

Did you ever figure it out we have the same issue.