Section 4 • Repair Procedures
March 2015
4 - 62
GTH-1048 • GTH-1056
Part No. 123701
MANIFOLDS
7-9
Valve Coils
How to Test a Coil
A properly functioning coil provides an
electromagnetic force which operates the solenoid
valve. Critical to normal operation is continuity
within the coil. Zero resistance or infinite resistance
indicates the coil has failed.
Since coil resistance is sensitive to temperature,
resistance values outside specification can
produce erratic operation. When coil resistance
decreases below specification, amperage
increases. As resistance rises above specification,
voltage increases.
While valves may operate when coil resistance is
outside specification, maintaining coils within
specification will help ensure proper valve function
over a wide range of operating temperatures.
Electrocution hazard. Contact with
electrically charged circuits could
result in death or serious injury.
Remove all rings, watches and
other jewelry.
Note: If the machine has been in operation, allow
the coil to cool at least 3 hours before performing
this test.
1 Tag and disconnect the wiring from the coil to
be tested.
2 Test the coil resistance using a multimeter set
to resistance (
Ω)
. Refer to the Valve Coil
Resistance Specification table.
Result: If the resistance is not within the
adjusted specification, plus or minus 10%,
replace the coil.
Valve Coil Resistance
Specification
Note: The following coil resistance specifications
are at an ambient temperature of 68°F / 20°C. As
valve coil resistance is sensitive to changes in air
temperature, the coil resistance will typically
increase or decrease by 4% for each 18°F / 20°C
that your air temperature increases or decreases
from 68°F / 20°C.
Description
Specification
Solenoid valve, 2 position 4 way
8.9
Ω
12V DC with diode
(schematic items AA, AD, AY, AAB and BAA)
Solenoid valve, 2 position 2 way
8.9
Ω
12V DC with diode
(schematic items AAC and EA)
DO3 valve, 3 position 4 way
5.6
Ω
12V DC with diode
(schematic items CA and EB)
Solenoid valve, 2 position 2 way
8.8
Ω
12V DC with diode
(schematic items FA)
Solenoid valve, 2 position 3 way
8.9
Ω
12V DC with diode
(schematic items CF, CO and CP)
Solenoid valve, 2 position 4 way
7.3
Ω
12V DC with diode
(schematic items CG )
Solenoid valve, 3 position 4 way
7.3
Ω
12V DC with diode
(schematic items DA and DB)
Summary of Contents for GTH-1048
Page 6: ...May 2015 GTH 1048 GTH 1056 Part No 123701 vi This page intentionally left blank ...
Page 174: ...Section 6 Schematics May 2015 6 11 Harness Map Control System Power Single Joystick 6 12 ...
Page 177: ...May 2015 Section 6 Schematics 6 14 Harness Map Control System Ground Single Joystick 6 13 ...
Page 178: ...Section 6 Schematics May 2015 6 15 Harness Map Control System Power Dual Joystick 6 16 ...
Page 181: ...May 2015 Section 6 Schematics 6 18 Harness Map Control System Ground Dual Joystick 6 17 ...
Page 190: ...Section 6 Schematics May 2015 6 27 Harness Map Options Work Lights 6 28 ...
Page 193: ...May 2015 Section 6 Schematics 6 30 Harness Map Options Road Lights 6 29 ...
Page 194: ...Section 6 Schematics May 2015 6 31 Harness Map Options Enclosed Cab with Heater 6 32 ...
Page 197: ...May 2015 Section 6 Schematics 6 34 Harness Map Options Enclosed Cab with HVAC 6 33 ...
Page 210: ...Section 6 Schematics May 2015 6 47 Hydraulic Schematic Models with Single Joystick 6 48 ...
Page 213: ...May 2015 Section 6 Schematics 6 50 Hydraulic Schematic Models with Dual Joystick 6 49 ...
Page 214: ......