Check ALL your grounds! Pretty much all my past "Mystery" problems in 12v is traced back to a ground somewhere.

 

I think my problem was similar. The ABS and battery lights illuminated for about a 1/2 mile on my 1990 Acura Legend and then went out. The other day I also noticed that this coincided with a more recent development: my radio power was not available when the ABS and battery lights came on, but when they finally went out, the radio came back on. I had a previous battery that was recently replaced (it was only a year old and couldn't take a recharge after my lights were left on accidentally), but even with the new battery I had the same problem. I took it in to the dealership, suspecting the alternator. It turns out that it was the alternator. Since it's been replaced, everything's been fine. Did you check the belt to the alternator?