Parking and Anti-Lock light stay on

[peobryant]

Went to start my truck up a couple hours ago to take my girlfriend home, and noticed my Parking brake warning light, and Anti-Lock light on the message center stayed on the whole drive. What could be the cause of this? This is the first time it has ever happened, and it is pretty annoying.

Thanks for any help.

[Richie O]

If you had her stay the night that would not have happened . My 89 has been that way since I put in my replacement rear end a few years ago. Have not looked into it. I am going to rip out the abs box just like I did on my 93.

[KTA]

I find that typically my lights come on when I have a vaccum leak somewhere. There is a sensor beside the brake booster that measures vac and if it is low those lights will come on. A bad sensor in the rear diff can cause it too.

[peobryant]

Thats how it usually works right, Richie?

Thanks for the info. Brian, I'll look into that.

[peobryant]

Any more info. on this brake booster? Where is it located, and what would I have to do to test it? Also, where is the sensor located in the rear diff?

Thanks

[PToombs]

Sensor on the rear diff is right on top, front side. The one for the vacuum is on the drivers fender, behind the hood hinge, towards the firewall. Follow the small line from the brake booster to the fender. See it? This one you can jump across to test.

[dpuckett]

When the RWAL/ABS light comes on, the BRAKE light comes on with it, warning that you have a "problem" with the brake system. Normally, it is just an isue with the ABS- you're better off unplugging the controller box, and bypassing the hydraulic dump valve on the left rear frame rail. No more light, have to relearn to drive it with good brakes. If you have one of the six that came off the line with good brakes and ABS intact, just unplug the controller and the light will go out.

WHen you replaced the rear axle, you likely didnt plug the diff sensor back in, making for the lights come on.

Daniel