Hey everyone I've had my 2007 Volvo s80 for a few months now and just today I was highway driving for 2 hours straight and as I got off my exit and came to a stop at the light my dash lit up like a Christmas tree and died out seconds after, this only occurs when I'm coming to a stop and it starts right up after a few moments. I tested battery and alternator and both were good. Totally clueless on this one.

 

does the car stall out when the dash lights come on and then you are able to restart? I'm wondering if the car is just stalling when you come up to the light with your foot on the brake and that's what is turning on all the lights. (ie engine stalls so your voltage drops and all lights come on. restart and the voltage is normal and no lights. You need to determine if you have a stalling condition (ie fuel pressure/fuel delivery etc) or an electrical issue (ie voltage/relays etc).