abs light on '95 nissan 2wd p-up

[pethia]

the abs light recently lit on my dash board. 1995 nissan 2wd pick up truck. The brakes are fine. Replaced fronts last summer. The rears were replaced about a year ago and should be ok. Could they be out of adjustment? I was working under the truck last week attempting to fix a leak on the top of the gas tank. I had to drop the tank down a bit to get at the stem leak. Are there any electrical sensors that may have been disrupted there in the rear that would cause this to happen? The truck brakes just fine.

[drjohn]

When the abs light comes on the brakes go back to normal brake operation. I believe 95 has the rear abs sensor on the diff. just behind the driveshaft. If the connection is broken or grease and dirt are in the trigger wheel the abs lamp will come on.