From my increasing experience with competition driving, I have learned that ABS braking is often not your friend, especially on loose surfaces. A sensitive touch has the capacity to outbrake the computer-controlled ABS system, particularly when we’re talking about the crude Subaru ABS computer.
This project aims to give the driver the option of driving with or without the ABS system functioning. It’s essentially the same thing as pulling and reinstalling the ABS fuse, but without having to crouch down and fumble around in the fuse box.
The first challenge was to find the ABS fuse. 99% of my Japanese car is signed in English, but one thing that is not is my fuse box. A quick Googling turned up a translated fuse box diagram which located the fuse as the third fuse from the back on the bottom row (20 amp).
My design for this project was to have a completely removable switch. My first thought was to have a switch permanently mounted, but when I discovered that there was more involved with accessing the ABS wires than I felt like doing I decided to got the easy way and just build a switch to replace a fuse.
I needed some wire terminals that could take the place of a fuse. You can actually buy what are called “spade terminals” that will (probably) fit right into the fuse slots, but I didn’t have any on hand and didn’t feel like going out to buy some, so I made my own out of some small ring terminals. I simply cut them down until they would fit in the fuse socket.
Sometimes, you just gotta work with what you have.
Getting these terminals to fit into the fuse slot required a small tweak to the fuse slot, as seen below:
On the ABS slot, indicated by the arrow, I used a small knife to remove just a tiny amount of plastic from the edge of the slot so the terminals could sit firmly in the slot without touching each other. The terminals will be insulated, but I felt better having more distance between them.
Next up is the switch construction. Because this is taking the place of a fuse, it also needs to incorporate a fuse. An inline ATC fuse holder comes to the rescue. This particular one had some mounting tabs and a spare fuse holder molded onto its sides, but they would get in the way of mounting the fuse holder and switch together, so they were cut off with a dremel.
Here is the switch and fuse holder ziptied together. Note that I have already crimped on a wire terminal to connect the fuse holder to the switch.
I didn’t like having the terminal exposed, so to avoid potential short circuits I added another layer of insulation in the form of heat shrink tube:
The aforementioned homemade terminals were crimped onto the fuse holder wire and another wire, they were again heat shrinked, and the switch is complete:
There is a nice little gap just under the hood release cable that this switch fit into perfectly. It isn’t attached to the car with anything, but sits quite securely in this spot. The wires were routed to the top of the fuse box where there is already a small gap, so no holes needed to be cut.
In the above picture the lower dash panel was removed, but this may or may not have been necessary for the installation of this switch.
With the switch in place, now I can choose whether ABS is on or off. It needs to be done before the car is started, as once it has been turned off it won’t return to normal operation until the car has been turned off.
I’m happy with this modification. I had been getting used to driving without ABS simply because I was too lazy to put the fuse back in between events, but it is potentially a benefit on ice and snow, and definitely a benefit for times when someone else drives my car.
Incidental supplies: (everything was found in my box of electrical parts)
ATC fuse holder
switch
female disconnect terminals
ring terminals (cut into spades)
heat shrink tube
wire
zip tie
This project aims to give the driver the option of driving with or without the ABS system functioning. It’s essentially the same thing as pulling and reinstalling the ABS fuse, but without having to crouch down and fumble around in the fuse box.
The first challenge was to find the ABS fuse. 99% of my Japanese car is signed in English, but one thing that is not is my fuse box. A quick Googling turned up a translated fuse box diagram which located the fuse as the third fuse from the back on the bottom row (20 amp).
My design for this project was to have a completely removable switch. My first thought was to have a switch permanently mounted, but when I discovered that there was more involved with accessing the ABS wires than I felt like doing I decided to got the easy way and just build a switch to replace a fuse.
I needed some wire terminals that could take the place of a fuse. You can actually buy what are called “spade terminals” that will (probably) fit right into the fuse slots, but I didn’t have any on hand and didn’t feel like going out to buy some, so I made my own out of some small ring terminals. I simply cut them down until they would fit in the fuse socket.
Sometimes, you just gotta work with what you have.
Getting these terminals to fit into the fuse slot required a small tweak to the fuse slot, as seen below:
On the ABS slot, indicated by the arrow, I used a small knife to remove just a tiny amount of plastic from the edge of the slot so the terminals could sit firmly in the slot without touching each other. The terminals will be insulated, but I felt better having more distance between them.
Next up is the switch construction. Because this is taking the place of a fuse, it also needs to incorporate a fuse. An inline ATC fuse holder comes to the rescue. This particular one had some mounting tabs and a spare fuse holder molded onto its sides, but they would get in the way of mounting the fuse holder and switch together, so they were cut off with a dremel.
Here is the switch and fuse holder ziptied together. Note that I have already crimped on a wire terminal to connect the fuse holder to the switch.
I didn’t like having the terminal exposed, so to avoid potential short circuits I added another layer of insulation in the form of heat shrink tube:
The aforementioned homemade terminals were crimped onto the fuse holder wire and another wire, they were again heat shrinked, and the switch is complete:
There is a nice little gap just under the hood release cable that this switch fit into perfectly. It isn’t attached to the car with anything, but sits quite securely in this spot. The wires were routed to the top of the fuse box where there is already a small gap, so no holes needed to be cut.
In the above picture the lower dash panel was removed, but this may or may not have been necessary for the installation of this switch.
With the switch in place, now I can choose whether ABS is on or off. It needs to be done before the car is started, as once it has been turned off it won’t return to normal operation until the car has been turned off.
I’m happy with this modification. I had been getting used to driving without ABS simply because I was too lazy to put the fuse back in between events, but it is potentially a benefit on ice and snow, and definitely a benefit for times when someone else drives my car.
Incidental supplies: (everything was found in my box of electrical parts)
ATC fuse holder
switch
female disconnect terminals
ring terminals (cut into spades)
heat shrink tube
wire
zip tie
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