ISSPRO R8480TM - Manual (Page 2)

Form No. IS107 - (Rev. C 11/29/2010) Page 2 of 4
If the number of cable turns per mile is not known, follow this procedure: Obtain a ratio tester and a correct drive tang for
your transmission. With a steel tape measure, mark off 1/10
th
mile (523 feet) in as straight a line as possible. Mark start
and stop lines with chalk or paint. Position the vehicle so that one of the wheels aligns with the start mark. Disconnect
the speedometer cable at the transmission and install the ratio tester in its place. Secure the cables and reset the ratio
tester. Drive the vehicle to the stop point positioning the selected wheel on the stop mark. The reading display on the
ratio tester is the number of cable turns per mile if using an Engler “SAC-10”. If using an SS Whit ratio tester (part
number 312-12175Y), multiply the reading by 10 to obtain the cable turns per mile.
Frequently Used Senders
Number of Pulses per Turn
Datcon 4-D-C 71267 8*
Dixson SG201A, SG201S1, SG202 2*
Engler 870-0588 15
ISSPRO R8970, R8940 30
Kienzle-Argo 8-161-237008 8*
Motorola 4-100(7SG100), 40-111 (7SG100B) 30
Rockwell 240R02-001 30
Sun Model CP7643 6*
Synchro-Start Minigen 30
Teleflex 9604276 8*
VDO (Old Style Engler) ISSPRO 300092 4*
Zemco 4710 8*
Zemco 6314 5*
*NOTE: These senders do not produce the minimum required number of pulses to be in calibration range when driven at
1000 turns per mile. It may be necessary to change your sender to one that generates more pulses per rev such as an
ISSPRO R8970.
Installation: Mount the speedo in the dash panel and connect the wires as described below:
Make all your connections to the black plug supplied and then plug it in to 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 Hints:
1. Bring both sensor wires back to the speedo connector. Do not 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 does not, 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 by 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).
The following calibration chart is for use with units that apply to direction sheet IS107 (R8480TM 3 3/8”
Programmable Speedometer Air Core Version.) If you have another application call ISSPRO for the appropriate
calibration chart.