JLG 120HX ANSI Service Manual - Manual (Page 72)

SECTION 2 - PROCEDURES
2-52 – JLG Lift – 3120686
2.24 BOOM MARKING TAPE INSTALLATION
Boom marking tape installation is shown in Figure 2-24.
2.25 BOOM LENGTH/ANGLE SENSOR
ADJUSTING PROCEDURE
NOTE: The boom length/angle sensor is factory set and nor-
mally does not require adjusting unless it is removed
from the base boom for maintenance purposes, etc.
Length Indicator Adjustment
1. Fully retract boom and place in horizontal position.
Make all adjustments with engine running.
2. On the load radius circuit card measure TP10 to
ensure that 10 (+0.1/-0) Volts DC is present.
3. Measure TP1 and adjust P1 until 1.233 Volts DC is
present at TP1.
4. Make the following adjustment with the power off.
a. Disconnect connector J2 (the 6 pin connector)
from the load radius circuit card. Measure
between Pin (1) of the socket connector and
ground (TB1-1) and potentiometer P5 to a value
of 1915 (+/- 5) Ohms.
b. Loosen the three (3) screws holding the 5K
potentiometer in the boom cable reel in place.
This enables pot/pot shaft to move freely.
NOTE: When checking the resistance on the 6 pin connec-
tor as outlined in step (c), be sure to use connector
pins (1) and (4) on plug 2 on the circuit card.
c. Rotate the 5K Ohm potentiometer until 100
Ohms is measured between Pin (1) and Pin (4)
on the 6 pin plug connector which mates with
J2.
d. Tighten the three (3) screws on the 5K Ohm
potentiometer in the boom cable reel.
5. Turn the power on and measure the voltage at TP2.
The measurement should be 1.287 Volts.
Boom Angle Sensor Adjustment
1. With the platform level, the boom completely
retracted and at 45 (+/- 1) degrees elevation, mea-
sure the DC voltage at TP5 on the load radius circuit
card.
2. Loosen the three (3) screws securing the sensor to
the box and rotate the sensor until 7.1 Volts is mea-
sured at TP5. Tighten the screws on the sensor.
3. Return the boom to horizontal.
Radius Adjust and Display Lights Setting
Procedure
1. Fully retract the boom and position it to horizontal
(zero degrees), with no load in the platform.
2. On the load radius circuit card, measure the voltage
at TP11 and adjust potentiometer P6 until 0.525
Volts DC is measured at TP11.
3. Measure the voltage at TP8 and adjust potentiome-
ter P2 until 2.223 Volts DC is measured at TP8.
4. Measure the voltage at TP9 and adjust potentiome-
ter P3 until 5.0 Volts DC is measured at TP9.
Figure 2-24. Boom Marking Tape Installation