Bronco: ABS Cut Off Switch

(NOTE: This article describes modification to the functioning of the ABS system and is intended for off-road use only.  Use the following procedures at your own risk!)

Those of you who have 1993-1996 Broncos have probably come across this problem, you’re going down a washboard road and suddenly have to hit the brakes. No matter how hard or light you hit the brakes you don’t seem to stop. Or you’re on a little expedition in some sand or snow, and you suddenly get stuck enough where your tires are spinning, you hit your brakes so you can put your truck into park without blowing apart the star and lo and behold your ABS turns on not allowing your wheels to stop until 5 minutes later. Fun isn’t it? Exactly, its a pain, isn’t it? Now for those of you who use their late model Broncos for daily driving know that the ABS, when you’re on pavement, works pretty dammed good. But, it can be deadly on the trail. Now, some of you have figured out how to disable it, and others are wondering how to disable it. This page will tell you how by a flick of a switch.

You will need some 16 gauge wire, a weatherproof toggle switch, male and female blade style connectors, silicone sealer (optional) some type of sheathing, two rubber grommets and a fuse holder, preferably the bladed type.

The tools you will need are a wire crimping tool, drill, a good wiring diagram, (I used the one out of the back of the Haynes manual) and a few hours time.

Start off by locating the PDB (Power Distribution Box) It will be located on the driver’s side by the windshield washer/overflow tank. Open it up till look a little like this:

The PDB on the driver’s side fenderwell

The PDB open, already wired up for the ABS Cut-off switch.

(soon there will be a schematic of the PDB here)

Take the fuse out of the second from the bottom (fender side) left hand side socket. This disables the brain of the ABS computer. Put the fuse aside. Next, drill a hole for the wires to pass through the firewall. Personally I used the Clutch blank, besides pulling the already cut insulation I know there is nothing on the other side that that can get damaged.

Open up the upper dash by removing the two trim pieces and taking out the Torx screws then set the parking brake and unlock the steering wheel and shift lever by turning the key forward but not enough to turn the truck on. Shift the lever down to 1st gear. Remove the headlight knob by taking a hooked piece of wire (hangers work great) and depressing the lock on the underside of the keyway. Now pull the dash off, enough to remove the 4W switch (if equipped) and the rear window roll up/down switch. You now can either drill a hole with the dash partially in place or you can take the whole thing off. Drill a 3/8 hole in the blank area of the dash (where it looks like switches would go right next to the 4x switch) and insert your switch, tighten the bezels up on your switch so it doesn’t move. Now, time to wire this whole thing up.

I put the switch here because it was convient

Go back to the PDB with your wire and fuse holder and cut two 6ft lengths of wire. Drill 2 1/4 inch holes in the lid of the PDB near the hinge and feed the wires through and insert the grommets. On the end of one wire add the fuse holder, on both ends of wire attach the male blade connectors. Stick the male blade connectors in the socket for the fuse and place the fuse in the fuse holder. Put the fuse holder upside down in the void at the end of the bottom of the center row of fuses.

Route your wires with their conduit over to the hole you drilled into he firewall. Be careful not to get the wires in the way of anything. Push the wires and conduit through the firewall. On the other side route the wires up to your switch. Hook up the wires to your switch. Turn the truck on and check that the circuit works; you will know if the ABS light goes off. If it doesn’t then flip the switch and turn off the truck then turn it back on. If the ABS light continues to light after initial testing then you have a break in your circuit, make sure the blade connectors are not loose and your fuse is securely in its holder and not blown. Once you have everything working button up the dash and go out wheeling! Note once you flip the switch you will not be able to turn the ABS back on until you turn your truck off then back on.

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