1998 Volvo XC70 alternator?

Hello, I have a 1998 volvo v70 awd xc, the other day it started acting weird, losing power, dash lit up, had them pull codes, said that it was running too rich (oil) and that I had bad gas. So, I put the gas treatment in to get rid of water, changed the oil (wife overfilled it), got the oil level to normal. Then, went to go start the car, dead, replaced with new battery. Then, put in new air mass meter, fuel filter, o2 sensors and the car will start, but, then dies after 5-10 seconds. I'm wondering what now? Also, would a low-output alternater cause this to happen, car not stay running? Wife not too happy with no progress on her car. So, please help. PS Now nothing is lit up on the dash, since new battery reset everything and I can't keep the car running long enough for something to light up.