Lincoln LT-7, Troubleshooting Manual

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TROUBLESHOOTING AND REPAIR
Observe Safety Guidelines
detailed in the beginning of this manual.
Troubleshooting Guide –
See Wiring Diagrams for location of specified
components. See Wiring Diagrams for troubleshooting of specific circuits.
B-18 B-18
LT-7 TRACTOR
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln
Electric Service Department for electrical technical troubleshooting assistance before you proceed.Call 216-383-2531 or 1-800-
833-9353
CAUTION
TRAVEL PROBLEMS
PROBLEMS
(SYMPTOMS) FIELD
COURSE OF ACTION RECOMMENDED SHOP
COURSE OF ACTION
The travel motor will not run with
travel switch set on “automatic”.
The motor runs properly with travel
switch set to “manual”.
The travel motor runs continuously
with travel control switch set on
“automatic”.
1. Check light 2H on logic board.
Light 2H should be lit when
automaic travel is required. If
light 2H does NOT light check
the coil resistance of relay 2CR.
Normal resistance is 10,000
ohms.
2. If 2CR coil is good and light 2H
does NOT light, when automatic
travel is required, the logic
board may be faulty.
3. If light 2H does light and relay
2CR activates the contacts in
2CR may be faulty.
1. Observe light 2H on logic board.
Light 2H should only be lit when
automatic travel is required. If
light 2H is lit continuously the
logic board may be faulty.
2. If light 2H lights only when auto-
matic travel is required and is
off all other times the contacts
in relay 2CR may be stuck
closed. Replace relay.
1. The travel control switch (S2) or
associated wiring may be faulty.
See wiring diagram. Check and
repair or replace if necessary.