I posted about this a few weeks ago, and after doing some checks as suggested I've run into a dead end. I get no code from the test port grounded with the ignition on (no blinking lights at all). I've cleaned and WD40'd the contacts at both plugs where the RWAL wires connect at the diff and up on the frame rail. I pulled out the RWAL sensor itself, cleaned and WD40d it. Anti-lock light still on. What should I try next?

The dash lights came on after actually employing the anti-lock in a panic stop about a month ago. Flash said something about a valve not centering maybe, but don't know where that is or what I could do about it. I suppose if I cannot figure it out I just need to confirm the rear brakes are actually still working and pull those bulbs out of the dash. It is starting to annoy me. But I am afraid that valve is stuck open or something and the rear brakes are actually sort of permanently anti-locked like in not working at all anymore.

Tks...

 

First off, are you keeping the test terminal grounded or just touching it to ground? You're supposed to ground it momentarily, 2 seconds or so.

A stop where the dump valve cycles a lot can set off a code. I take it the lights are still on?

 

Yep. It sounded like something was cycling it's butt off when I hit the brakes that one time. The rear end of the truck was literally shuddering for a couple seconds until I let off.

I can hear something click under the hood, like a relay closing, but no lights blink anywhere on the dash. This is when grounding that little single-post connector behind the glovebox.

 

the black 2 prong connector with one wire in it is shorted(2sec) and the anti-lock light is on and don't blink.......I would say the arwal computer is bad........ Hmm didn't you say the the rear brakes pulsated when you did a panic stop?

if it did then the system is working properly.

Do the brakes fill bad or is it just the light on all the time that is the problem.

 

Brakes seem fine, but dash light is on. Where is the RWAL computer?

 

Behind the glove box, just above and to the right of the black conector,... you jumped, Right?

Is it the anti-lock brake light that is one or the brake light, or both?

 

Yes, shorting that pin does nothing. Both lights (anti-lock and brakes) stay on.

 

It's just real strange that, the grounding of that wire didn't do any thing but, when you did a panic stop, the anti-lock system worked

 

Unplug the module and the light goes out.

 

Woo-hoo! Warning lights are out, finally. Thanks spunbearing. I confirmed the rear brakes are actually working. So I'm assuming now without RWAL? Wonder if that RWAL module, computer or whatever the heck it is is still available? I never did like anti-lock brakes anyway. I always thought a good driver could stop better without 'em.

 

You might try to plug it back in. The computer module will reset. If there is a problem the light will come back on. If it was just a fluke with the panic stop it should stay out.

 

That would have been nice, but unfortunately the warning lights are on with the module plugged in.

 

I drove my truck with the module unplugged for months. I changed my sensor etc. with no luck. Finally I drained my axle flushed it really well and changed the fluid. My light went out and has been working perfectly since. I guess that there were just enough small metal particles in the gear oil to foul the sensor. It all started after I lifted the back end of my truck to change the rear drums and shoes.

 

Now that you mentioned it there was a fair amount of that metallic goop that builds up in the diff on the sensor when I took it out to check it yesterday. I'll try pulling it again and cleaning it better this time. The gear oil in there only has about 3,000 miles on it, so I really don't want to do that job anytime soon.

 

the wire that u remove to get the rear sensor out of the diff,.......the wire go up to the frame and has a nether connector.
remove that wire and us a ohm meter and see it it has a lot of resistants or has a open.

most rwal failures are form the wire!

I think that when us grounded that terminal for the codes you grounded it to a peace of metal that was insulated by plastic.
try it again with a none go ground!