The battery and charging system were tested and deemed to be in proper operating order. I am pulling 14.35 at the alternator and 14.20 at the battery and 13.7 and 13.5 under load, respectively.

After something in the range of an hour or two of driving....and on an intermittent basis...the instrument cluster acts up and the fuel gauge drops...then the car eventually dies. At the point the battery is too weak to start the car.

I may have damaged the system earlier when I jumped it after leaving the interior light on, and reversed the polarity (eek!). I feel pretty stupid about this.

Couple of things to add:

1. My ABS system is dead. No codes, no idiot light, no ABS breaking.
2. The battery is less than two years old and the alternator is a remanufactured unit installed AFTER the polarity mishap.

Are there grounds I should check?

1. Where are they?
2. Could the ABS fuse behind the knee bolster cause this?
3. Could a bad solder connection in the cluster cause a huge drain that running out the battery and sucking the amps out of the alternator?

BTW the local volvo-only independent does not want to look at the car. Cannot say that I blame him. There are no parts to sell.