Up until now, there has only been one wiring option available for the MY18+ Toyota Prado, which has quite an invasive installation process, requiring most of the dash to be removed. Even though there are some plug and play components to the harness, it is mostly a clunky process, which also requires the use of a drill bit to install the switch. If you ask us... a 'plug and play' harness should be exactly that... 'plug and play'...
We as STEDI are notoriously known worldwide for our truly non-invasive plug and play high beam harnesses, and the new Prado is now no exception. Unfortunately due to the more advanced CanBus system installed into the Prado, picking up a simple high beam trigger from the headlight proves to be quite a difficult proposition. Fortunately, the indicator/high beam stalk is still running on a simple analog system. This is where we need to plug our piggyback adapter in.
Due to now having the piggyback adapter inside the vehicle (as opposed to the headlight), you will need to both enter and exit wiring from the vehicle. We have optimized the length of the piggyback and placed a rubber grommet on the wiring to install through a factory hole above the accelerator pedal. This is the easiest way to exit the piggyback from the vehicle. Of course, you will still need to enter the switch wiring into the vehicle with our harness wiring instructions.
Now, let's get into the installation instructions.
Step 1 - Open the driver's door and locate the small panel on the end face of the dash (this can be found adjacent to the hinge). Place a broad face implement or trim tool behind the plastic and lever up enough to fit your fingers behind. Once you can get your fingers behind, pull and remove the trim and set aside for re-installation later.
Step 2 - Locate and remove one Phillips head screw and one 10mm headed bolt from the lower edge of the trim piece near your knees. Once these are removed, pull the entire lower-trim away from its mounts, and carefully set down in the footwell.
Step 3 - You now need to remove the steering column lower trim piece. The upper part can stay, however, to remove the lower piece, you first need to turn the steering wheel 90deg to the right and remove one Phillips head screw, and likewise 90deg to the left, and one screw. Remove this trim and set aside for later refitment.
Step 4 - Locate the 20way plug and unplug from the stalk body.
Step 5 - Open out the STEDI piggyback adapter and plug the 20way male and female plugs into their respective plugs (label 1) and neatly route the wiring along the column, adding cable ties to hold the wiring. (make sure that the steering wheel can move up and down, and telescope in and out without stretching the wires)
Step 6 - Locate the 'scotch lock' (label 2) and crimp it on to the solid green wire located behind the AHB (auto high beam) switch. The piggyback adapter will not work without this connection.
Step 6a - The wire labeled * can be used for the dash illumination power feed for the switches. Simply connect this to PIN 5 on the Square Toyota switch.
Step 7 - From inside the engine bay, locate the black blanking grommet on the driver's side firewall, directly behind the brake master cylinder. The above picture denotes its approximate location. Remove this from the engine bay side and discard it. You will see the white sound deadening through the hole; your wiring will need to go through this. With a friends helping hand, get them to hold a screwdriver or pointed implement into the white insulation. From the inside, locate where the screwdriver is pushing through, and slice the carpet section to allow the wire to enter the hole.
Step 8 - From the engine bay side, pull through all the remaining wiring and neatly cable tie the wire under the dash. Make sure there is no possibility of getting caught on your feet or pedals.
Step 9 - Make sure the rubber grommet (label C) is seated properly into the firewall.
Step 10 - Cable tie across the engine bay and assemble the 'red' wire into position 'A' and 'black' in position 'B' in white T-plug. This can then be plugged into the main wiring harness.
Step 11 - Follow the harness installation instructions to guide you through installing the main harness.
Step 12 - Re-assemble the dash trims in reverse order.