2005 & up Xterra & Frontier Atlas Install

*Navigate Xterra Installtion by using the Xterra Installation navigation payne on the left.

If starting with a 2WD vehicle, no electrical modifications will be needed. This section may be skipped. The speedometer reads vehicle speed from the wheel speed sensors. No speedometer changes are needed. The stock electrical transfer case is fully integrated into the vehicle computer system. Vehicles starting as 4WD must have the transfer case control module plugged in or there will be error codes in most of the systems that share the CAN data buss. The transfer case control module needs to see all its signals for it to be happy as well. On the transfer case there is a shift motor with a 7 pin connector and 3 position sensors elsewhere on the case. The shift actuator (7 pin) should have been removed from the transfer case. It needs to be plugged back in. Use a 1” PVC pipe cap from the local hardware store and a little epoxy to cover the shift actuator to keep dirt out. Note that the cap is taller then the motor output, this keeps it from binding.

Securely attach the shift actuator in a safe location and don’t forget to attach the vent hose. We relocated it under the rear floor as our spare tire was moved to a bumper mount. The harness may be lengthened without problem to mount the actuator in a good location.

The actuator is controlled by the transfer case computer; it also has switches inside that feedback to the computer the position of the motor. The other 3 switches on the transfer case confirm that the transfer case has shifted to the desired position as commanded by the shift motor. Leave these 3 sensors unplugged; we can trick 2 of them under the dash, the third we don’t worry about. That third one is a non-detectable circuit that will not cause errors in the computer. Its main purpose is to warn you that the transfer case is in neutral when you shift the transmission into park. Since the Atlas II does not have a neutral position sensor we cannot hook this up. With the 7 wire plug on the actuator hooked up, the plug with the red wire (Neutral detect) is abandoned; this leaves 2 plugs that need to be connected.

The plug with the yellow wire connects to the low range switch; this is the switch on the rear axle shift rail. The plug with the orange wire connects to the 4WD switch; this is the switch on the front axle shift rail.

Using 2 relays to eliminate the dash knob function: The relays and position switches on the transfer case will send the correct signals to the transfer case computer. The rotary 4WD switch on the dash will no longer be used.

The basic operation is one relay engaged when in 4WD, making the correct electrical connections for 4HI operation (power switching from 2WD to 4WD for the dash knob signal and grounding the 4WD detect switch so the computer sees that the request to shift into 4WD has occured). The other relay engages in low range and provides all the correct connections for low range use (power switching from 4WD to 4LO for the dash knob signal and grounding the 4WD detect switch so the computer so the computer sees that the request for shifting into low range has been completed). When both are off, it is set up for 2WD (Power sent to the 2WD dash knob position so the computer knows it should be in 2WD, 4WD and low range switches off to confirm 2WD operation).

Keep this page handy and refer to it while building the relay harness. Note: different relay manufacturers may number there pins differently, they are not standardized. You need to match the function of the relay, not necessarily the pin numbers.

We used 2 of these relays from a local electronics shop. Important details are 12V coil and DPDT (Double Pole Double Throw). The contact ratings do not have to be this high (10A) as there is only milliamps going through them. Overly large relays should be avoided as well as they may draw too much power and blow the fuse for the transfer case computer. If the relays are only rated for “momentary use” do not use them, they will burn out.

Relays laid out, ready to make harness. Taping them together keeps them stable and easier to follow the instructions.

Lay out 8 tags for each of the wires in the finished harness. We used masking tape.

First wire, power. Connected to all 3 terminals as listed in the diagram. Be sure to attach the labels to each of the wires.

Follow the connections as mapped out. Don’t forget the jumper between both relays (blue wire above)

The relays with the wire organized into there functions. Power, 4LO, 2WD, 4WD are to replace the dash knob (and power the relays) 4WD transfer case and 4LO transfer case take signals from the transfer case switches to cycle the relays 4WD detect feeds a signal to the computer to tell it that it is in 4WD (high or low range)

Now to install the relays in the vehicle.

Remove just this one plug; all splicing will be done to this plug only. Remove the plastic sheath to access the wires better. There will be several splices and taps, you will need room to work.

This is the pin layout as looking at the back of the plug (wire side)

Pin #24, yellow wire (located between a red wire and a white wire). Cut wire in two. Harness side: connect to relay harness “4LO transfer case” Plug side: splice into pin #11, white wire (located between a light green and a brown wire). Do NOT cut the white wire, splice only.

Pin #17, orange wire (end of the row next to a white wire) Cut wire in two. Harness side: connect to relay harness “4WD transfer case” Plug side: connect to relay harness “4WD detect”

Pin #16, white wire (located next to #17 from step above). Cut wire in two. Harness side: cap, not used Plug side: connect to relay harness “4LO”

Pin #15, orange wire (located next to #16 from step above). Cut wire in two. Harness side: cap, not used Plug side: connect to relay harness “4WD”

Pin #14, green wire (located next to #15 from step above). Cut wire in two. Harness side: cap, not used Plug side: connect to relay harness “2WD”

These 3 wires (and power connected below) take place of the dash mounted shift knob.

Pin #6 Black wire. Spice in relay harness “Ground”

Pin #25 White wire (next to yellow wire from the first splice). Splice in relay harness “Power”

Underfloor wiring:

The shift motor needs to be plugged into the 7 wire harness. It may be possible to attach the motor to the floor and not lengthen the harness. If you choose to mount the motor in a different location, lengthen the harness as needed. As long as the vent is connected the shift motor may be located at any safe, convenient location. Be sure to protect from excessive heat. There are 3 other plugs (2 wires each) that were also disconnected when the transfer case was removed.

The plug with the black connector can be abandoned. The 2 connectors with gray plugs need to be attached to the Atlas shift switches. Use the new connectors that fit the Atlas.