1997 Ford F150 4.2L V6 Automatic 4WD with rear ABS- The rear ABS seems to have stopped working although it was working last week during a snow storm. Over the past few days I have had to stop short and the rear wheels locked up and skidded. I also came to normal stops on some compacted snow and the rear wheels skidded too which is not normal for this truck.

More info: I checked the brake fluid level and it is fine. I checked the dash for lights and none are on. When I turn the key to the on position, only the yellow ABS light turns on, the red brake light does not. I took apart the instrument panel and swapped bulbs and the red brake light still does not come on.

I replaced the ABS sensor on the rear differential a couple years back for another issue. One thing concerning me is the ABS Unit/pump under the hood is fairly rusty. Please go to this link for a picture of it: https://docs.google.com/leaf?id=0B0v...ZDkyMDFi&hl=en

Any ideas what is going on? Thank You

 

have you checked the fuse panel???