The 93 is an RWAL system only. The module is behind the glove box and the valve is on the left frame rail near the rear axle. You can't buy any new parts for it so most guys just bypass the valve and disconnect the module.
It was recommended to me by a local mechanic but it's not that easy , at least not for me as the ABS light and the brake warning light are lit without the module in place. With an inop module in place the brake light is out but the ABS light flashes and that triggers a safety inspection fail. I could remove the light bulb but I'd rather have it working for now.
I'm not sure what the 93 system is like but Google it and see what comes up on other truck related forums, that is how I was able to figure out some of what I was dealing with once I got codes .
What lights are on ABS , or abs and brake ?
Read this ,
abs and brake light 1it also mentions a sticky but I found nothing in it .
Also read this
abs and brake light 2
