1991 Pontiac Grand Prix ABS pump keeps running

WE have this 91 Grand Prix GTP with the 3.4 DOC with a strange ABS system. The ABS keeps running and we had to take the fuse out when the car wasnt running. Now the fuse keeps blowing. Dealer says its a junk system and cant get parts for it and cant find a pump for it. Been told it could be sensor or something else that keeps it running but not sure. She has just put $1700 into the car and now this and cant drive it. Any suggestions?

Thanks
Keith