Jamar RAC-100, Manual

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Installing the
Modular Distance Sensor
Most newer vehicles (1992 and newer) have an electronic speed output
rather than a mechanical speedometer cable coming from the transmission.
With the newer vehicles you will need to install either a Modular Distance
Sensor (MDS) Vehicle Kit or a Modular Distance Sensor Quick Kit. Use
the following instructions for installation of the MDS Kits.
1. Find a location under the vehicle
dashboard that will allow fairly easy
access to the MDS. Do Not mount the
MDS on the heater ducts or where the
heater vents will blow directly onto it.
Attach the MDS using the nylon ties
or Velcro provided, as shown in Figure
2.1.
2. Locate the 2 wires coming from the Vehicle’s Speed Sensor (VSS).
• On most Ford and Chrysler pick-up trucks, the best place is on the
rear end differential housing using the rear ABS signal.
• On General Motors pick-up trucks, the best place is the VSS at the
transmission.
• On many vehicles (both trucks and autos) you can go to the cruise
control signal or to the vehicle ECU which is often located under the
dashboard.
(Your local Auto/Truck dealer can usually tell you
where the VSS can be located on your vehicle. If
you need additional assistance, contact JAMAR.)
3. Route the red and black end of the 20’ grey
VSS cable through the firewall. This can usually be done by using an exist-
ing rubber grommet where other wires pass through the firewall. If you
cannot locate an existing hole, CAREFULLY drill a small hole large enough
for both the VSS cable and the +12Volt/Ground wires. EXTREME CAU-
TION must be taken to insure you do not drill into anything mounted on
the opposite side of the firewall or cut any existing wiring.
2-3
Chapter 2 — Installation
All wires and the
MDS itself should be
kept away from any
heat source that
could cause melting.
Figure 2.1
MDS Mounted Under Dash