Electronic Speedometer Conversion for Renix Jeep Cherokee XJ/Comanche MJ

For Jeep owners with a mechanical speedometer gauge, specifically 87-90 year Jeep Cherokee XJ and Comanche MJ, there's a recurring issue with the cable causing a bouncing speedometer.  This is due to the low quality of replacement cables and the difficulty of routing them without excessive bends.  To fix this, we've developed a kit to allow you to upgrade to a 91-96 electronic speedometer and sensor.  This is entirely electronic and uses no mechanical cables and fixes the bouncing speedometer issue!

It took awhile to develop this kit and ensure it was fully functional and easy to install.  We spent a lot of time testing different parts, getting components from the junkyard, and reviewing wiring diagrams before finally landing on this solution.

At a high level, you will be removing your existing mechanical cable and replacing it with a 3-wire harness that connects from a standard electronic speedometer sensor.  For the gauge cluster, you will be removing the existing mechanical gauge and installing the electronic gauge in it's place (with some modifications), then connecting the gauge to the sensor with the new harness.

Required Parts

  • BoxyJeep Conversion Spacers (front + rear + screws) - This allows you to mount the electronic speedometer in place of the mechanical one with proper offset and alignment.
  • 87-90 Original Gauge Cluster (blue) - Unfortunately 84-86 will not work for this conversion.  You can confirm that you have the right cluster if all of your gauges screw in from the rear and you have a blue square with X through it behind the speedometer.
  • 91-96 Speedometer (white) - You can grab one of these from the junkyard, eBay, or from our store.  While you don't need the entire cluster, you likely also want to get the bezel and acrylic cover so you don't need to re-drill the hole for the trip reset.  The speedometer gauge screws into the cluster with 3 screws from behind.
  • BoxyJeep 3-Wire Harness (approx. 8 ft) - This connects from the gauge cluster to the sensor (IGNITION + GROUND + SIGNAL).  We sell this or you can make your own.
  • Speed Sensor - OE (5234422 or 56027726) or Dorman 917-654 or SC105T (includes pigtail).  If you do get an OE sensor, make sure to cut off the wiring pigtail!  The 90's Chrysler sensor is proprietary and no longer made.
  • Sensor-to-Speedo-Gear Housing Adapter - OE 52069315 and can be found on 90's Cherokee, Grand Cherokee, Wrangler, Ram, or sold through our store.

Gauge Cluster Installation Process

  • 91-96 Cluster Prep - Remove the front cover and bezel from the cluster, and then unscrew the speedometer gauge from behind by removing the 3 screws.  Remove the gauge from the front.  Once removed, unscrew the plastic spacer on the back of the gauge by removing the 3 screws.  Ensure the circuit board does not come dislodged.
  • 87-90 Cluster Prep - Remove the front cover and bezel from the cluster, and unscrew the speedometer gauge from behind by removing the 2 screws.  Remove the gauge from the cluster and also remove the rubber isolator and 2 bushings.
  • 87-90 Cluster Clearance - Depending on which specific revision of the cluster you have, you'll need to use a Dremel tool to remove some of the backlight bezels.  Test fit the 91-96 speedometer gauge to see what needs clearance.  It's a good idea to remove all other gauges and bulbs to prevent damage during this process.
  • Sandwich Plate Installation - Once clearance has been created for the new gauge, place the front sandwich plate into the gauge cluster so it sits flat.  Use a 3.5mm drill bit to drill through the 3 holes to the rear of the cluster.  Place the rear sandwich plate in place and ensure the holes align straight through.  The rear plate should click into position.
  • Gauge Installation - Now that the sandwich plates are in place and holes drilled, install the 91-96 speedometer gauge and screw into place with the supplied M3 screws.
  • Assembly - Reinstall any removed gauges and bulbs as well as the bezel and clear front cover. 

Wiring

  • Overview - The wiring is quite simple; there are 3 wires necessary to run the gauge.
    • IGNITION - Power from ignition source (orange)
    • GROUND (black)
    • SIGNAL/SPEED (white)
  • The wires jump from two other terminals on the back of the cluster for IGNITION and GROUND, and connect directly for the SIGNAL/SPEED wire.
  • Full wiring diagram can be found here.

 Connectors

  • Speed Sensor - OE speed sensors use a proprietary 90's Chrysler/Dodge connector that is no longer available.  If you source an old sensor, be sure to grab the pigtail.  Newer replacement sensors use a APEX 2.8 3-pin female connector.
  • Cluster - While not required, a 3-pin Deutsch connector is included with our kit to make it easy to remove the cluster.
  • Gauge - 3mm ring terminals are used to connect to the back of the gauge.

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