Volvo: electrical problems, v70 cross country, repair attempts

Question
i have a 1999 V70 cross country.  Since Feb the car has been in and out of the shop trying to fix the same problem.  Here are the symptoms:  the head lights dim and blink off; the radio will make a popping sound and then quit; the ABS, TRAC and BRAKE light come on on the dashboard, the car will chug and try to stall out.  These things all occur at the same time and when the car is going slow (usually under 1500 rpms).  I was told the car is going into LIMP mode but no one can seem to find out why. These are the repair attempts: 1 ABS modulator; 3 alternators; 2 batteries; 1 alternator belt; 1 ETM software upgrade; and the ground wire from the battery was cleaned and re-attached.   Do you have any other suggestions?

Answer
Angi,
All that I can add is to have the system's codes read and see what that tells you. Also try to recall if just prior to this all beginnning, was there anthing that happened? Make sure that the ground wires under the intake manifold are all in good shape and tight.. Actually look at all the ground wires that you can find under the hood, making sure that they are tight.