Both the ABS and regular brake lights are on. (4 wheel ABS.) When they are on the ABS does not work. It is also kinda intermittent, working one week, then not the next. I neep help, no one around here has the scanner end for my truck except the dealership, and they want 75 bucks just to diagnose. I need to know what to test in order to pinpoint the problem. It seems to stop working in wet/high moisture conditions. I also noticed that the yellow switch on the proportioning valve doesn't seem to do anything, (I took it out and cycled it with an ohm-meter and got nothing) so I'm not sure if that may be an issue... any ideas would be great! Was told it was most likely rear wheel sensor...

 

it's kinda tricky accessing the ABS diag connector on these pre-96 trucks. If you have a dead wheel speed sensor or an intermittent problem, you can check it by disconnecting the sensor and connecting an AC voltmeter, then spin the rear tires. It should fluctuate between 0 and 5V AC. If it doesn't that could be your problem.

 

hmm well that i can try... I've already had the rear sensor connector off to check the wire resistance, guess i need to do that next. Would that also be the same for the front?

 

hi, pull the rear sensor out, it might have metal on it from the rear gears, thus shorting out the sensor,,, my 2cents.,,, tom

 

x2 on the rear wheel anti lock sensor (RWAL). This is VERY common. Actually have the same problem right now and haven't gotten around to fixing it. Another issue that causes those lights to come on is low brake fluid and worn out brake pads.

The RWAL sensor is located on the top of the pumpkin on the rear end. There is a wire with a plastic module which is bolted to the top or the pumpkin. Remove the bolt and pull up on the sensor.

If all else fails, check your ABS wiring and sensors on your wheels.

 

Here is a great video on fixing the sensor. The Dakota is newer but same part and hookup...

http://www.wonderhowto.com/how-to-repair-abs-speed-sensor-dodge-dakota-truck-244165/\


Here is the sensor... Found HERE

 

Replaced RWAL sensor, everything was working, thought all was good. Went through a puddle last night and this morning it was inop again. It seems like when it gets wet, high moisture etc that it doesnt work, and when it dries out its ok and works fine.

I also just had new brakes put in (lines, front pads, wheel cylinders) and all air is bled out, so I know thats all good. The one thing i was wondering about is that little yellow switch in the combination valve. It only has one wire going to it. Can anyone tell me what this does and what resistance its supposed to have when functioning properly? mine seems to have no resistance, and was wondering if it should