Well, I finally fixed this today. I had the truck in at the dealer for an oil change this past week, and they also had a coupon for a free diagnostic code reading, so I thought I'd see if they could read the RWAL codes from the CAB with their diagnostic tool. They ALSO were unable to read a code. They did say they checked the fuse and it looked fine, and they didn't see anything obviously wrong with the wiring. So, I was still stuck in the same place.

I was on a vehicle-repair tear today, as I helped my step-son fix a couple issues on his Volvo 940 wagon this morning. So, I decided to look back into the trouble with the ABS warning lights today. HeyYou - I printed out the section of the repair manual with Diagnostic Test 6 for the RWAL CAB and started stepping through that. I also printed out the relevant section of the wiring diagram for the RWAL circuit.

The problem: Fuse #20 - STOP LAMP was blown. I replaced the fuse and the warning lamps went out. I had also pulled another CAB (Controller, Anti-Lock) from another 1996 Ram in the u-pull-it yard today, just in case, and I tested that in my truck, too (that spare looks to work fine, too).

So, when checking the fuses for the Rear Wheel Anti-Lock control unit, you need to make sure that BOTH fuse #14 - RWAL/ABS (20A, this circuit is switched with Ignition) and fuse #20 - STOP LAMP (15A, this circuit is a constant battery feed) are OK.

Again, the symptoms that presented were that BOTH the BRAKE and ABS warning lamps were lit on the dash, and I was unable to retrieve diagnostic codes from the ABS unit. This makes sense, now, as the ABS unit did not have BOTH of the power feeds that it needs.

 

I had the ABS light and the Brake light come on yesterday as I arrived in Austin (200 miles from home). After parking for about half hour, it was gone when I starteed it back up. Today the lights showed up again. No codes on MTG 2500,

Checked and swapped fuses (no tools, no parts with me). If I slowly pump brakes before starting, I do not get the lights. Have to go 200 miles southeast tomorrow and tow a car back home on car dolly. Think I will go to a local brake shop here in Austin to get brakes bled in the morning. If I cannot clear it, I don't feel safe towing a car.

Have FSM on laptop...going to do some reading shortly (at the bar....)


UPDATE - Took truck to Brake Check in Austin Saturday morning and asked them to bleed the brakes. He told me he had to pull all the wheels off to check ABS. Told him no, the only thing for that was on pumpkin. He wanted to argue - untill I told him I had 2300 page FSM on laptop. "Bleed brakes and we"ll go from there!" Bled brakes (they felt a little soft and I cannot bleed them alon at a downtown hotel parking garage...) They charged me $75, but being out of town there was no other option available.

 

I fought and fitted with my abs and brake light staying on for 3 months. I only have rwal on my 97 ram. I read all the posts here and replaced the speed sensor, chased wires and cussed a little. I got into my dashboard fuse box today to change a blown power outlet fuse and noticed my tailight fuse was blown too. changed the taillight fuse and presto, no more abs and brake light. guess I've been driving for three months now with no brake lights. Anyways, I hope this helps.

 

hi i have a 98 dodge ram 1500 extended cab rear wheel drive truck with steady abs and brake light indicators. these two lights have been on for years lol but i want to get rid of them now. I checked the abs speed sensor on the rear axle and cleaned it of metal flakes. I did not replace it, only cleaned it, because there is no problem whatsoever with my speedometer nor cruise control. could the problem be from the abs sensors at each wheel?? also, i have removed the abs/rwal fuse to get rid of the always on brake light so that i can tell if my parking brake is on or not when driving, but the abs light is still on.

 

The 97's and later use a different ABS system - you'll need to connect a diagnostic computer to read out the error code, I believe, and then you can understand what is wrong and what needs to be fixed (the 96 and earlier RWAL allowed a workaround to get the error codes to blink out).

As for why the warning lights are still on with the fuse pulled, I believe the circuit to the warning lamp is designed that way - so that the error light is lit if the ABS unit doesn't have power (as that would be an error condition, too). The ABS unit has to turn the light off, after its self-check on power-up, if everything is OK.

 

I have a 2000 Dodge Ram 2500 that has the Abs/Brake light on. It just started the other day when I started up. After I left it sit until after work it did not come back on until the next morning. Now it is on all the time and the speedo doesn't work along with the trans seems to be not shifting right. Checked all the fuses and fluids and all are fine. Any suggestions?

 

Replace the rear wheel speed sensor that sits on top of the rear differential. That's where speedo signal comes from as well. Should solve all your listed problems.

Welcome to DF!

 

Disconnect negative battery cable before replacing the sensor.

 

Thanks so much guys. I will get right on that today.

Update: I replaced the sensor and all is well. Thank you guys so very much!!!!!!! It took longer to drop the spare tire than to change out the sensor. Thanks again. You guys rock!!!!