This kit is a quick in term fix for the Jeep TJ Rubicon’s and JK’s. We are working with a firm that is designing a circuit board to that will provide all the same functions as the stock low range switch found in these Jeeps. This in term kit only tells the computer system that the Jeep is in low ratio, disabling the ESP on JK’s and enabling the locker option on the TJ Rubicons. If this kit is used, we highly recommend upgrading to the new switch when it becomes available.

In essence the Low-range switch tells the computer what mode the transfer case is in. To operate the needed functions on these vehicles, we find the need for only one of the normal four possible mode positions, and that is the “Low-Range” mode. This mode allows the factory lockers (and electric sway bar if equipped) to work on the Rubicon series TJ & JKs. The other necessity is the ESP (ELECTRONIC STABILITY PROGRAM) in the JK series of Jeeps. By installing the Low-Range switch in the JK’s it will automatically turn the ESP to its lowest setting possible. Allowing front digs in low range, tire slippage without engine hesitation or braking feedback. It will also change the fly-by-wire throttle sensitivity to take away the side affects that usually consist of jerky throttle response that occurs as a result of running low range without the Low-Range switch hooked up.

How It Works

The requirement for the TJ (Rubicon) series & JK in low range is 62 Ohm's of resistance. By utilizing a couple parts from an electronics store, you can make the Jeep work like stock, without any major changes or computer system re-configuration.

REQUIRED PARTS:

• Qty: (2) 33 Ohm Resistors
• Qty: (1) p/n 300378 (low range switch)
• Qty: (2) p/n 300378-c (male plug w/ connectors)
• Qty: (1) p/n 300378-f (female plug w/ connectors)
• Qty: (1) 12" 16 gauge wire

Step 1: From your local electronics store or online retailer you will need to acquire two 33 Ohm resistors. By soldering these in series you get 66 Ohms resistance (Fig.1). Remember stock was 62 Ohms. The closer you can get the better. However a slight percentage off will not have any ill effects on the switching.

Step 2: You will want to use a marine grade heat shrink tubing or at the least standard heat shrink filled with silicone. Working your way from the center out with your heat source, shrink the tubing down around the resistors. (Fig.2) Now install new ends (Preferably the AA Weather resistant style included with p/n 300378-c & 300378-f) as per steps 3 through 7.

Step 3: Strip wire insulation back enough to slide it into the metal contacts.

Step 4: Slide rubber grommet onto wire before crimping. (Fig. 3) The round non ribbed side of the rubber grommet needs to face the newly stripped wire.

Step 5: Slide the metal contact back on crimping it down, leave the two large prongs sticking out.

Step 6: Solder the crimped section

Step 7: Slide the rubber grommet into the 2 large prongs, when crimping the connector make sure to also crimp the rubber grommet in with them. (Fig. 4)

At the one end of the wiring you will need a male plug (p/n 300378-c) to fit into the Atlas low range switch, a female plug (300378-f) will be necessary for the opposite end and another male plug (p/n 300378-c) to replace the factory end on the wiring loom.

It should look like something close to this depiction when ready to be installed (note the low range switch plugged into the end of the harness ready to be threaded into the Rear shift rail side of the Atlas, making sure to remove the white plastic washer from the Atlas): (Fig.5)

You will now need to cut off the factory wiring loom low range end. Follow steps #3 - #7 again, installing the new male end.

Plug your new Low-Range Resistor pig tail in. you should now be able to put the rear shifter in "N" neutral or "L" Low and the factory dash cluster will show "4WD" and on JKs the traction control light will illuminate. (Fig.6)

If you are running an Atlas 4 speed the same still applies with a few exceptions: If you only use 2.72 (planetary) it will not see low range which will not allow lockers, electric sway bar disconnect or automatic ESP disabling. Also if going this route with the Electric shifter on the Atlas 4 speed you will need to make a spacer (fig.7) & rotate the motor up (Fig.8) to gain enough clearance for the plug & switch on the side of the Atlas.