Textron Jacobsen Super LF 1880 Fairway Mower with ROPS, Инструкции по обслуживанию и ремонту

Страница: 199 / 300

ELECTRICAL SYSTEM
10G-19
WATER TEMPERATURE SWITCH
TEST
The water temperature switch is used to warn the oper-
ator if the engine coolant temperature exceeds safe
limits. The switch is mounted at the base of the upper
radiator hose opposite the coolant temperature sender.
The switch can be tested as follows:
1. Shut down the engine and remove the ignition
key. Allow the engine to cool completely.
2. Remove the wiring harness connector from the
switch.
3. Set the multimeter to the continuity scale.
4. Touch one test lead at the base of the switch;
place the other test lead on the threaded stud that
holds the wiring harness connector
(Figure 10G-3).
Continuity should not be available at the switch.
NOTE:
If the switch indicates continuity and the engine is
cold, replace the switch.
Figure 10G-3. Coolant Temperature Switch
PARKING BRAKE, NEUTRAL
START, REEL POSITION, AND 4WD
DROP OUT PROXIMITY SWITCHES
TEST
GENERAL
The proximity switches used on the LF-1880 are nor-
mally open switches, which means no current can
travel through the switches until activated. When a con-
ductive metallic object (such as steel) is moved near
the surface of the switch a set of reeds are closed cre-
ating a path for the movement of current through the
switch. During the test it must be determined if the
switch closes (continuity) and how long the switch
stays closed (sensitivity).
CONTINUITY TEST
1. Shut down the engine and remove the ignition
key.
2. Set the multimeter to the continuity scale.
3. Connect one test lead to a connector plug socket
and the other test lead in the other plug socket.
Continuity should not be available when no metal-
lic object is present in the sensing area.
4. Connect one test lead to a connector plug socket
and the other test lead in the other plug socket.
Pass a metallic object (such as a small screw-
driver tip) across the sensing area of the switch.
Continuity should be available and resistance indi-
cating 0 to 0.5
Ω
(OHMS) while the metallic object
is present in the sensing area.
WARNING
Because the proximity switches are used primarily
as safety devices it is extremely important that the
switches be operational and not be bypassed or oth-
erwise tampered with. Serious injury and or property
damage can occur if the switches are bypassed or
tampered with. Replace any switch that does meet
the requirements of the following tests.