ABS light related at all to power steering?

[99GTPOS]

I recently replaced my power steering pump. It had the pump with the variable ratio assist, and I replaced it with the non-variable ratio type pump. This means that the connector that operated the variable ratio is left hanging. Ever since I did this, the ABS light has been on. I don't think I noticed it on before, but I guess it might not be related. I have a grinding noise coming from the rear of the car, but it is pulsating with speed... sounds like a warped rotor. When I brake, it goes away. Anyone know if the ABS light is somehow related to the variable assist steering, or do I have another problem?

[99GTPOS]

I guess I should also post that my "check tire pressure" light has been on for months, but i assumed it was due to the fact that I put two different tires on the front and back- backs are original goodyears, fronts are something else. Maybe this has something to do with it?
Rant---> You know, idiot lights are great, if they would tell you what the f'ing things are for! If not, they aren't worth anything! end rant.