ABS, Trac off, Service Engine Soon Lights...

Hello,

I have a 2003 pontiac grand am with the ABS, Trac off, Service Engine Soon Lights coming on. Once they come on, if I let the car sit and off for about an 1 hour or so the lights won't be on. Until I drive it awhile and they will be back. Is that the hub and sensor causing the messages to come up? It is weird because I just replaced them at 30,000 and the car has 70,000 now. When I replaced them at 30,000 I could hear a grinding from the bearings. Is there a special spray I could use to clean the connectors? What is the likely hood that it is the wiring harness leading into the car?

Thanks in advance

The wiring go to the sensors is often the problem as the wiring is exposed to the elements and subject to damage . I'd check for anything obvious and make sure the wiring is secure and not flopping around .