Main Trn Len Sw Disagreement - JLG 1250AJP Troubleshooting Manual

SECTION 1 - FAULT DICTIONARY AND SELECTED TROUBLESHOOTING

1.230 MAIN TRN LEN SW DISAGREEMENT

Flash Code: 8-4
Main Transport Length Switch Disagreement. The two main boom transport length switches are reading the same state. As
in Figure 2-2. Dual Capacity / Transport Switch Mounting on Pg. 179 and Table 2-3. Switch States / Boom Length Regions on
Pg. 179, the main boom transport length switches should always read opposite, except at the A/B and C/D transitions.
Note Pretest Instructions
1.230.1 Access the main boom
transport switches #1
[X054] and #2 [X055]
1.230.2 Access the main boom
transport switches #1
[X054] and #2 [X055]. Fully
retract the boom. Note the
cam strips that the switch
levers ride upon on the side
of the fly boom.
1.230.3 Access the main boom
transport switches #1
[X054] and #2 [X055]. Fully
retract the boom.
1.230.4 On right side of boom
access the main boom
transport switches #1
[X054] interior terminals.
Ground multimeter.
1.230.5 Fully retract main boom.
Ground meter near tower
boom passthru [X044].
Take the following measure-
ment by backprobing. See
Grounding and Backprobing
on Pg. 319 for details.
1.230.6 Fully retract main boom.
Ground meter near main
boom transport switch
passthru [X047]. Take the
following measurement by
backprobing.
1.230.7 Fully retract main boom.
Ground meter near MTB
passthru - 21 position
[X042]. Take the following
measurement by backprob-
ing.
1-118
Test
Are any of these switches stuck or frozen
Are the switches and cam strips mounted so
that the switch levers engage the entire length
of cam? Are the cams and switches securely
mounted? Also, are the switch levers mounted
at 90° to housing as seen when not engaging a
cam?
Are both switches off cam?
Turn on machine. Measure voltage on main
boom transport switch #1 (top) [X054] termi-
nal 22 (white wire) and terminal 21 (black
wire). Do they both measure about 12 volts?
Turn on machine. Is there about 12 VDC on
tower boom passthru socket B [X044.B.soc].
Turn on machine. Is there about 12 VDC on
main boom transport switch passthru pin A
[X047.A.pin]?
Turn on machine. Is there about 12 VDC on
MTB passthru - 21 position socket B
[X042.B.soc]?
1250AJP
Result Corrective Action
Yes Clean/repair/replace as needed
No Keep access to the switches open.
Go to step 1.230.2
Yes Keep access to the switches open.
Go to step 1.230.3
No Repair as needed
Yes Check for mechanical failure of the boom tele-
scope cylinder mechanism
No Keep access to the switches and the boom in the
same position.
Go to step 1.230.4.
Yes Keep machine in same condition.
Go to step 1.230.8.
No Go to step 1.230.5
Yes Keep machine in same condition.
Go to step 1.230.6
No Keep machine in same condition.
Go to step 1.230.7
Yes Repair/replace switch wiring between main
boom transport switches #1 and #2 (top and
bottom) [X054] [X055] and main boom transport
switch passthru [X047]
No Repair/replace harness between main boom
transport switch passthru pin A [X047.A.pin] and
tower boom passthru socket B [X044.B.soc]
Yes Repair/replace harness between MTB passthru -
21 position socket B [X042.B.soc] and tower
boom passthru socket B [X044.B.soc]
No Repair/replace harness between MTB passthru -
21 position socket B [X042.B.soc] and Power
Down Relay [X011]
3128411