Brake Light Pressure Switch Relay Instructions

brake light pressure switch relay

There are four connections to this item and it can be connected up in one of two ways:

• Black Wire – Connect to the vehicle chassis in a convenient location
• Red Wire – Connect to a 12v source, either from the existing 12v in to the pressure switch using the spade terminal piggyback connector or directly from the fuse box using the supplied extension cable and piggyback connector (if required) on the fuse box.
• White Wire – Connect to the other side of the pressure switch
• Blue Wire – Connect to the wire that did come form the pressure switch and goes to the brake lights

connecting by sharing the incoming 12v feed

The pressure switch has two wires, one a 12v feed and the other going to the brake lights themselves. You will need to identify which wire is which using a multimeter if you do not have a wiring diagram. Disconnect the wires one at a time so as not to confuse which is which.

Using the supplied spade piggyback connector, you will need to join the incoming 12v feed wire to the red wire on the plugpal brake light pressure switch relay.

Disconnect the wire from the other side of the pressure switch, the one that goes to the brake lights, and connect this to the blue wire on the relay harness. The white wire is then connected to the remaining pressure switch terminal and the black wire from the relay can be connected to ground.

connecting by providing a separate 12v feed

This is the better way of connecting the relay, but does require a small amount of extra work as it entails using the supplied extension lead to run from a 12v feed at the fuse box to serve the relay.

Again, you need to identify which wire on the pressure switch is providing 12v but this time you leave it connected. As before, the wire to the brake lights can be disconnected from the pressure switch and connected to the blue wire and the white wire can be connected to the pressure switch, the black being connected to the vehicle chassis to provide a ground connection.

The red wire is connected to the extension cable and then run to the fuse box and using the spade piggyback connector (if required) it is connected to a suitable feed.