dan239

I will probably try this later today. I do question if this will effectively disable the abs to the point where it will not take the brakes away. I will test it to see.

Daniel

dan239

I tied the front pair together and the rear is tied as originally hooked up. I am not getting the warning lights now. However I can still try an emergency stop and get the same brake release, but it comes in much later. Now, I have to get both front wheels to be about to lock up to get the taking away of my brakes. I am going to leave it this way and see if I can live with it [pun intended].

If someone has a way to completely disable the abs system with no warning lights and no loss of the speedometer, please respond.

Thanks to all who have made suggestions.

Daniel

rickf

https://www.dieseltruckresource.com/...s-t303990.html

See post #6. This is exactly how my 98.5 is so yours should be the same. Unless you have the manual transmission, that may be the kicker.

Rick

j-fox

I'm not sure why it worked on my truck but not yours. Is there a different tooth count somewhere?
I believe the rear wheel sensor is the speedo too. You have effectively made the truck a 2 axle anti-lock (anti-stop).

NE frmhnd

Did you try to hook the front wheel sensor feeds in to the rear sensor the opposite way? Maybe it was reading that your front wheels were traveling backwards or something?

dan239

No, I did not try that because I keep the positive and negative wires together. Trying that could feed voltage backwards into the CAB and possibly burn something up in it. I do not think I want to risk it.

Daniel

NE frmhnd

If both wires come out of the controller I don't see how that could be a problem.

dan239

If you connect a positive and a negative wire together you will be creating a short and the results or unpredictable. I am not willing to risk it.

Daniel

rickf

Most automotive computers work on a 5 volt signal. They send out five volts and read the return for the value. In this case the return is an alternating state signal read as a square wave. A dead short would most likely result in a blown ECM fuse but I don't think I would want to risk my computer to find out! I think I know what the problem is with tying them all together is. The rear tone ring is much larger in diameter than the fronts. That means that one revolution of the rear is going to be a different number of pulses than the fronts. This is most likely accounted for by software in the ECM and when they were all tied together it was sensing the fronts were slower than the rears. There should be another tone ring at the rear of the transmission where my speedo is, you say yours is on the rear diff. You would need a graphing meter to read the square wave to be able to compare frequency of fronts to the speedo signal. If they are the same you could use that instead of the rear wheel sensor. Is the truck a 4X4? Put it on a lift in 4 wheel drive and idle it in gear and read the frequency of each sensor and that will give you something to work with.

Rick

j-fox

I ahve been very busy.

Do you have the rear sensors wires tied to all three inputs at the ABS unit?
Leave the front sensor wires hanging in the air.
Sending one input signal ( the rear) into all three computer inputs should work. I'm not reading it that way with your responses.

dan239

This is the way I had them connected [rear sensor wires tied to all three inputs at the ABS unit] when I was getting the warning lights coming on after about 500 feet of driving. Now I have the fronts connected together and into both front inputs on the CAB. The rear sensor wires are connected to the rear inputs. I am not getting the warning lights now. The abs system is not taking my brakes away as soon as it was in factory condition.

Daniel

duster75

bypass the brake lines going into the abs valve.Did this on several 1st gen.s to get rid of it. Nate

dan239

I have considered this but I have not come up with a simple way to do it. There are two lines going into the HCU [Hydraulic Control Unit] and three lines coming out. I would have to tee the two fronts to the front line coming from the master cylinder and connect the rear line from the master cylinder to the rear line removed from the HCU. If the threads are the same I could remove the line to the rear from the HCU and put it into the master cylinder. However the fronts are not so simple.

Daniel

brianshog

I have a 1998 3500 4x4 12 valve with 4 wheel ABS brakes and I want to disable the system also because I am tired of trying to locate the issue with them I seen there are 2 plugs up on the CAB and the 2 wires a black and red that looks like they come from the HCU up to the CAB which ones would you unplug to disable the ABS system I have had my front wheels lock up a couple of times for no reason and I am tired of the issue with ABS