KDSS On/Off Switch for the 5th Gen 4Runner – Install & Review

KDSS On/Off Switch for the 5th gen 4Runner by Dr. KDSS (2014 – 2022)

Let’s talk about the KDSS On/Off Switch for the 5th Gen 4Runner, GX460, and GX470.

The main benefit of this mod is that you can turn KDSS on or off at any speed with the push of a button. It’s a switch that allows you to turn on/off (as the name implies) your KDSS system’s valves. When the switch is turned on, it turns KDSS off. When KDSS is off, the system valves stay open at all times. That means they will not close over 12mph.

In a normal KDSS application (without the switch), the system’s valves are open under 12mph and closed at speeds of 12mph+. Under 12mph the KDSS valves are open which allows for the oil/piston’s to move freely through the interconnected hydraulic lines. Over 12mph it closes the Valves which puts pressure on the lines ultimately making your ride more controlled, and stiffer. So with the switch enabled (KDSS off) this keeps the valves open at all times.

KDSS is great on-road but off-road the stiff sway bars add some rigidity to your ride quality when you’re pushing over 12mph off-road – especially if you’re not aired down. When KDSS has been activated over 12mph and you’re on the trail, it’s stiff, somewhat rocky, and can be quite jarring on the body. With KDSS off when off-roading over 12mph, however, the ride is much more comfortable and forgiving. It’s a much more enjoyable experience when hitting whips, dips, and ruts when KDSS is off.

Find it online: 

• Dr. KDSS Website: Check Prices

What Does the KDSS Dr. Recommend? 

You really feel it when off-roading and driving around town. My recommendation is to have it in soft mode when off-roading (off) or driving around town under 40-50 miles an hour. Then once you get on the highway and start hitting 50+ speeds, you can turn on KDSS and revert back to the factory speed-sensitive stiff mode. If you have a heavy load or you’re towing, you want to have the factory mode engaged. You will enjoy your ride even more having more control of how it feels, both on and off. If the KDSS light is on it stays in soft mode. If the KDSS light is off it acts like normal and is speed-sensitive. KDSS will be in the soft mode under 12 miles an hour and stiff mode over 12 miles an hour. – Dominick Dr. KDSS

How did get Dominick Dr. KDSS Get Started? 

The KDSS switch actually started by Dominic when he was working with a company by the name of Blackgate Customs. Dominic has since left the company and has now redesigned the new KDSS On/Off switch. Previously, the switch was designed to connect to the harnesses along the frame rail near the KDSS actuator. Now the KDSS switch is located in the cabin near the gas pedal.

“I’m staying away from Blackgate”

“I’m staying away from the outside frame rail area where the KDSS pump is at. Other than me completely changing the wiring design due to an electrical theory, it’s also being moved to inside the cab because once you pull the connector off, it’s most likely not going to get the same seal it had from the factory. Trust me, all my data logging is proving that. Let’s keep it all inside away from the elements all with a new and improved wiring harness and integration system”. – Dominick Dr. KDSS

KDSS Switch – What is it

The new Dr. KDSS On/Off switch comes wired in a wiring harness with dual relays. It’s two connector harnesses that interrupt your KDSS electrical system, and then a positive and negative lead that you can connect to a switch of your liking. You won’t need to know how to wire relays as everything is pre-wired for you. Just connect the ground and hot for the relays and you’re good to go.

Using a KDSS On/Off Switch with Switch Pro?

Some guys in the industry have reached out to comment on the KDSS switch on whether or not running a relay with the switch Pro or a similar device is a good idea. The complaint is extra amperage and the additional relay on one circuit can mess up the Switch-Pros main unit. To answer all those comments… I have almost 30,000 miles of testing the KDSS On/Off switch setup running on a Switch-Pros. – Dominick Dr. KDSS

He has stated that the actual relays on the switch will get warm but that’s to be expected and absolutely nothing to worry about. There are two relays on the KDSS Switch and the lead that will go to your Switch-Pros, when hot, is drawing .32 amps. Not even half an amp.

Installation Overview

The first thing you want to do when you start installing the switch is to test it. Turn your 4Runner on “accessory” (on but without the engine running). Unplug the white connector from the KDSS module. KDSS light will come on the cluster. Plug it into the KDSS harness controller. Take the factory connector on the harness and plug it back into the KDSS module. The KDSS light will turn off. This is only to test your unit. If the KDSS light does not turn off, you may have a faulty unit. If the relay fails for whatever reason, it will revert back to stock.

Tools and Materials

• Heat Gun
• Wiring Loom
• Heat Shrink
• Wire Strippers
• Wire Cutters
• Plastic Pry Tools
• Utility Knife
• 18AWG Wire
• Kline Crimps
• Metric Sockets
• Surgical Scissors

• The updated switch has new colors for the wires on the dash switch (red, green, blue, and black )
• The black wire from the KDSS harness goes to the fuse box bolt
• The red wire from the KDSS harness goes to the green wire on the dash switch
• The red wire from the dash switch will be the wire you use to go back to the fuse box to grab power using the fuse tap
• The blue wire on the dash switch will go to illumination + wire on neighboring switch
• The black wire will go to a variable ground wire on a neighboring switch

Step 1. Wiring Overview

Here is a look at the wiring overview.

Step 2. Connect Switch Wire to Add-A-Fuse

The green wire on the switch connects to the add-a-fuse.

Step 3. Black/Red Switch Wires to T-Taps

Connect your t-tap connectors to the red and black wires on the switch.

Step 4. Switch Wire to Add-Fuse and KDSS Switch

The main red switch wire connects to the red wire coming off of the KDSS switch harness. Now is a good time to also connect a terminal for the ground.

Step 5. Pull Back Weather Stripping

Let’s get that harness installed. Start by pulling back this weather stripping.

Step 6. Plastic Pry Tools Switch Console Plastic

Take a pry tool, and pop this plastic trim panel off so you can access the switch blanks.

Step 7. Pop Out Center Switch Black

Squeeze the two tabs on the switch blank and pop it out.

Step 8. Cut Out Plastic Taps

UPDATE: 

The new manufacturer of the switch button is Air On Board out of Australia and they got the switches to function so well now with no mods at all. You no longer need to cut these small tabs off. 

Step 9. Connect KDSS Switch Module

Let’s run this KDSS module. Start by unplugging the factory KDSS clip and then plug in the new KDSS switch harness. Then plug the factory KDSS clip into the new KDSS switch harness. Now run the switch harness over the steering column shaft.

Step 10. Run KDSS Module Up to Switch Blanks

Prepare zip ties on the KDSS switch harness.

Step 11. Secure KDSS Module & Connect Add-A-Fuse

Zip tie the dual relay to the left side of the brake pedal bracket with the wires facing up. 

Step 12. T-Tap Green and White Wires (Defroster Switch)

• The updated switch has new colors for the wires on the dash switch (red, green, blue, and black )
• The black wire from the KDSS harness goes to the fuse box bolt
• The red wire from the KDSS harness goes to the green wire on the dash switch
• The red wire from the dash switch will be the wire you use to go back to the fuse box to grab power using the fuse tap
• The blue wire on the dash switch will go to illumination + wire on neighboring switch
• The black wire will go to a variable ground wire on a neighboring switch

Illumination + and variable ground on the neighboring switch:

2010-2019 4Runner you can use the front defrost switch to t-tap into for illumination and variable ground.
–  dark green is illumination + wire
–  light gray is variable ground

2010-2019 gx460 you can use the trac off switch to t tap into.
–  dark green is illumination +
–  white with black pin strip is variable ground.

2020+ 4R use front defrost
– white is illumination +
– green is variable ground

2020+ gx460
– green illumination +
– white w/ blk stripe is variable ground.

If you want your Dr. KDSS to switch to illuminate and have the factory dash cluster dimming sensitivity, you can connect it to the defroster switch wires. Connect your T-Taps on the defroster switch wires to the green wire and the white wire. Make sure your T-Taps are making a good connection on the wires. Sometimes it helps to spin the T-Taps around the wire to fully cut the sheathing on the factory wires in order to make a solid connection.

Step 13. Insert Tap Wires (Black/Red from Switch)

• Black – White
• Red – Green

Now zip everything up and put your dash plastics back together.

Final Thoughts

After cruising around with the KDSS valves open over 12mph, it really does make a difference. We pushed the 4Runner pretty hard offroad at around 40mph+ against some jagged rocks in the mud and it works. We were impressed with how the suspension responds to the looser sway bars. The compression is definitely softer and the rebound isn’t so jarring which makes it really easy on driver comfort. With this KDSS switch on, it’s almost like airing down your tires without airing down. Pretty wild.

I dig it. Anyway, let me know if you have any questions.