ABS light?

[mikeyb1965]

hi guys,

my name is Mike, I live in Maine, and just bought a new to me 2000 GMC Sierra extended cab 4wd pickup. the truck is in pretty decent shape, needs the typical rocker panels and a cab corner, for living its life in maine, and has 197,00 miles on the clock. it has the 5.3 litre engine and runs very strong.

my question is this.....the abs light is on in the dash and i am wondering if anyone can give me some insight as to where to start looking first. the wheel bearings are good and tight and dont know if this could be a sensor. the friend i bought the truck from said his mechanic told him he might have to replace the block that all the brake lines connect to, but i figured i would come ask the pro's....awesome forums by the way, i have read and drooled in almost all of the sections. you guys do some beautiful work.

thanks in advance for any help, or directions you may send me....Mikey B.