Switch to disconnect the ABS pump fuse

[Tim@NCTSLLC]

Switch to disconnect the ABS pump fuse

This weekend I hooked up a 12v relay and an in cab switch to allow mw to have push button convenience to disconnect the ABS pump fuse.

Here is what you will need.

One - 12 VDC Automotive 5-Pin Relay SPDT 30/40A
Two – 14/16 AWG (Blue) Male spade lug
Four – 14/16 AWG (blue) Female Spade lug
Two – 16/18 AWG (red) Female spade lug
One – 16/18 AWG (red) ¼” post ring tongue lug
One – 16/18 AWG (red) #6 post ring tongue lug
One – #6 x 3/8” self tapping screw
Three – 6” long #14 AWG Red conductor
One – 24” long #18 AWG Red conductor
One – 48” long #18 AWG Black conductor
One – 24” long #18 AWG Black conductor
One – Push button or toggle switch (only needs to be rated at 1 – 3 amps)
Electrical tape or heat shrink.
Solder or additional lugs to connect to your switch.

Depending on the relay, either cut off the plastic mounting tab, or remove the metal mounting tab from the slots on the relay so it will fit neatly down in the slot next to where you will remove the fuse.

The relay will have five terminals marked 30, 85, 86, 87A and 87.

Make sure the relay has the post configuration above or it will not function correctly!

The 87 terminal is NOT used for this installation, when the relay is activated, this terminal will have 12v positive power on it, so it could be used to light an indicator light to alert you to switch position if desired.

Installation

Remove the ABS Pump fuse from the power distribution center under the hood. This should be a pink 30 AMP cartridge fuse. Check your owner’s manual to identify the correct fuse; it will be listed as for the “ABS Pump”

Take the two 6” long red conductors, and crimp a female spade lug on one side, and a male spade lug on the other side of each of the conductors.

Plug the male spade lugs into the sockets on the bottom of the pink cartridge fuse you removed.

Tape or apply heat shrink over the connector’s and fuse body for protection and to prevent the lugs from being dislodged from the fuse.

Plug one conductor into a male spade sticking up in the fuse box where the cartridge fuse was removed.

Plug the other end of the second conductor on the 87A terminal on the relay.

Take the remaining 6” long conductor, and crimp a female spade lug on each end.

Plug one end of the conductor into the other male spade sticking up in the fuse box where the cartridge fuse was removed.

Plug the other end of the conductor on the 30 terminal on the relay.

Take the 18” long black conductor and crimp the #6 stud ring tongue lug on one end. Connect the other end to your switch (either a lug or solder depending on the switch).

Take the 48” long black conductor and attach to the other terminal on your switch (either a lug or solder depending on the switch).

Mount the switch in your desired location.

Attach the end of the 18” black conductor with the #6 ring tongue lug to a ground using the self tapping screw or an existing screw under the dash (must be a solid ground).

Route the long black conductor out through the fire wall and to the power distribution center.

After routing to the fuse box area, trim off any excess so that it comes up in the open area of the fuse box from underneath (space is next to where you removed the fuse), and crimp on a red female spade lug.

Connect the black conductor to either the number 85 or 86 terminal (makes no difference) on the relay.

Take the 24” long red conductor, install a red female spade lug on one end, and connect to the 85 or 86 terminal on the relay (the one you did not use above).

Route the lead out of the fuse box from underneath and over to the 12V post on the battery.

Trim the conductor to length and install the blue ¼” post ring tongue lug.

Attach the lug to the battery post by removing the 10MM nut and placing the ring lug under the nut.
Retighten securely.

Test the relay.

Make sure your switch is in the OPEN (off) position with the relay de-energized. This is the normal everyday driving state.

Start the vehicle and verify that there are no dash indicator lights on for ESP, ABS, and BAS.

Change the switch position to the CLOSED (on) position, and verify that the three indicator lights for ESP, ABS, and BAS illuminate on the dash. If so, the installation functions correctly. If not, recheck your wiring.

Place the switch in the OPEN (off) position and turn the vehicle off.

Note, that the dash lights will stay illuminated; we will cover that in a moment.

Neatly route the wiring down into the open slot in the power distribution center along with the fuse and the relay. Refer to the photos.

Close the lid and you are done.

Now, how the switch functions.

Whenever you place the switch in the CLOSED (on) position, you energize the relay which breaks the connection for the ABS pump fuse. It is best to do this with the key off, but if need be, you can do this with the vehicle running.

When you activate the relay, all three lights will illuminate on the dash indicating that ESP, ABS, and BAS are disabled.

In normal driving on dry pavement, you are unlikely to notice any difference in your braking abilities other than ABS will not activate.

To restore operation, turn the switch to the OPEN (off) position to de-energize the relay. You must cycle the ignition key off, restart the vehicle, and drive a few feet forward and the indicator lights will go out indicating that system operation has been restored.

I do not advise ever using this anywhere but at the race track, and NEVER use this in inclement weather, as your ability to control the vehicle in slippery conditions will be greatly impaired.

USE AT YOUR OWN RISK!

I will add some pictures later this evening.

[HEMIBeast]

Awesome write up!

[Joe in PA]

Sweet write up!