I have a 93 D250.The antilock and brake lights are on all the time. My book suggested to ground the RWAL diagnostic connector and count the number of flashes to read the code. Sounds great BUT does any one know where the connector is and how am i to ground it. My book is geared towards a mechanic and i am not one ( just hate to pay someone else to fix my stuff ). Thanks for any info.

 

im not sure if this is related to your problem or not but i recently had this happen to my truck. turns out the shop i had replace my brakes shoes (a large nationwide chain in fact)failed to notice a bad wheel cylinder and the computer would through the code everytime i stomped on the brakes since rears were basically not engaging at all. im sorry i cant elaborate on it more buti dont want to attempt to explain somethin i dont completely understand [undecided]

 

I am by no means a Master on this but just went through the complete thing myself. RWAL connector is located behind your glovebox (at least on 4wd model). I had bad rear brakes but even replacing them, Brake light still on. I bled the antilock valve in the back above axle on frame, still lights up. I did disconnect the RWAL connector for 5 mintues. That reset that light and it stayed out for a couple of days. Then started having other electrical problems. Come to find out, Fuse # 9 in fuse box controls Directionals, Tach (if have one) & RWAL. Once I fixed that, everything looking good. Fuse wasn't blown but seemed loose and had to pinch the connectors within the fuse box so fuse was tight again. Hope this helps because it was getting frustrating to say the least.

 

I have the same problem with my 91'. I just had the brakes completely done but the light is still on. My cousion has the same truck with the same problem. Have you found a solution?<br>

 

If you don't mind resetting your stereo time and stations, just pull the positive lead connector on the battery for about 2 minutes to reset the computer. My 89 did that a couple times but finally quit. I think my sensor in the diff was dirty and once I had changed the oil a couple times it cleared. Also the connections at the Diff can get some water in them and with the road salt give some false alarms.. Try cleaning the connections to the sensor in the diff and clearing the codes..<br><br>If that all doesn't work, alot of guys just pull the RWAL plug off the controller and never plug it back in..<br><br>J-eh<br>

 

I appreciate the responses to my question, sorry IO haven't responded back I have had to go out of town on buisness. I found a thread about this connector(rwal control module) it is behind the glove box. I grounded the black wire of the connector and I received a fault code of 9 (the lights will blink on/off for the number to read. A code nine indicates speed sensor wiring/resistance (usually high reading). so now I guess my speed control sensor is bad, unless I have a broken wire or bad connector making thr resistance go high. Does anyone have any ideas on the troubleshooting.

 

More likely just a wet or corroded connection at the top of differential where sensor is. Pull it off and dry/clean up. Petroleum Jelly (Vaseline) seems to make an excellent waterproofer for 12 volt systems, for me anyway. It does not attack rubber. Good luck.

 

Thanks sootblower, I just tried to clean the connector to no avail. I think it's time to put a new sensor on. Autozone wants $30.00. That's not to bad, unless anyone has anymore suggestions.Thirty bucks could buy some fishing lures.

 

I had the same problem with my 93 D350,, I replaced my power booster now my light are out and my brakes work like they should.. I can even use my air controls for the A/C and heater. I checked vac pump and had 25&quot; of vac but did'n have good brakes. Had to really push on the peddle to get her to stop. just though I would give you this info. might help<br>

 

I have only had my '93 d250 4x2 for 5 weeks. The first week I had it, the antilock and brake lights lit up. Scared the soup out of me! I contacted the previous owner since he told me the front brakes were recently changed. PepBoys did the damage, I mean work on it and they said they'd check it out for free. However, they couldn't get the light to light up. I turn it on pressed on the brake pedal and wala, it lit up! They didn't know squat! I then took it to a brake specialist who has worked on my other trucks(non diesel) and vehicles. After 2 hours checking it out, he told me he just bled the brakes and could not duplicate the problem, but now the brakes work much better...much firmer feel on the pedal. Needless to say, I haven't had the problem since. That was over 1k miles ago and its still working great. However, he did mention that if it did come on again he recommends that I change the master cylinder.

 

sorry It took so long to reply, my modem fried and I just replaced :'( My trucks light turned out to be the antilock speed sensor ( on top of the tranny) It's going to run around $90.00 to replace. Needless to say I have not done that yet. The truck seems to stop just fine. i will eventually get to it. thanks for the info every little bit helps, knowledge is power.

 

ABS works about as good as the rear adjusters or emergency brake. Probably wouldn't hurt to have a cinder block and chain on the back just in case.