ISSPRO R8480 - Manual (Page 2)

Form No. IS073 (6/21/01 Rev. B) Page 2 of 4
INSTALLATION: Mount the speedo in the dash panel and connect the wires as described below:
Make all of your connections to the black plug supplied and then
plug it into the speedometer’s white connector.
RED – Connect to ignition switched power source.
BLACK – Connect to ground along with one of the sensor wires.
GREEN – Connect to dash lamp power.
WHITE – Connect to other sensor wire.
INSTALLATION:
1.) Bring both sensor wires back to the speedo connector. Don’t connect the sensor ground wire to a point which is physically different
than the speedometer ground.
2.) WHEN POWER IS APPLIED, THE NEEDLE SHOULD GO TO THE ZERO POSITION. IF IT DOESN’T, THERE MAY
BE A BAD CONNECTION IN THE “HOT” (RED WIRE) OR GROUND WIRE CIRCUIT. CHECK POWER TO THE
METER BY MEASURING WITH A VOLTMETER AT THE PLUG (METER LEADS ON THE PINS THAT ATTACH
TO THE RED AND BLACK WIRES). IF THERE IS POWER AT THE PLUG, THE PROBLEM IS IN THE GAUGE.
3.) Low voltage (below 10.5 volts) will cause inaccurate reading. If inaccuracy is suspected, measure voltage with vehicle operating
and meter connected. This can be done by connecting a voltmeter to power source (i.e. fuse block, etc.) and/or piercing the red and
black wire insulation with the meter leads.
4.) If speedo reads zero, then “jumps” to normal reading after a certain speed adjust the sensor in closer to gear (generators cannot be
adjusted).
5.) A bad ground will make the needle erratic.
HINTS:
Finding tire revs per mile:
The best source of finding tire revolutions per mile is by contacting your tire dealer. However, if the information is impossible to get,
use the following procedure:
1.) Check the tire revs per mile:
a. Mark the tire and floor directly below the center of the hub.
b. Move the vehicle one revolution of the tire and mark the floor corresponding to the mark on the tire.
c. Measure the distance between the two marks in inches. Use this distance in the formula below to find the tire revs per mile:
63,360 Divided By Measured Distance = Tire Revs Per Mile
2.) After calibration the meter per instructions, if you will find the meter still runs too fast or slow try the calculations below to fine turn
calibration:
Drive at a known speed and note the speed indicated on the speedometer. A good way of doing this is by following a vehicle with a
calibrated speedometer. Next, with the following formula, use the numbers obtained and the original calibration number to calculate the
correct calibration number.
(Old calibration number) X (MPH shown on meter) = New Calibration number
(Actual MPH)
EXAMPLE:
The vehicle was actually going 55 MPH while the speedometer shows 60 MPH. The meter switches are set for calibration number of 39,847.
39,847 X 60 = 43.469
55
The new calibration number for this meter is 43,469. Refer to calibration chart (pages 3 and 4) and find that switches 1,2,3,6,7 and 8 will be
in the “on” position.
The following calibration chart is for use with units that apply to direction sheet #IS073 (3 3/8” Programmable Speedometer Air Core
Version.) If you have another application call ISSPRO for the appropriate calibration chart.