DRESSTA TD-25M EXTRA - Service Diagnosis

ELECTRICAL SECTION 8
Page 23
DRESSTA TD-25M EXTRA
SERVICE DIAGNOSIS
4. SERVICE DIAGNOSIS
When performing any service diagnosis on the electrical system, refer to the wiring diagram to
identify the various electrical components and for tracing the wiring of the problem circuit.
Before performing tests, check the following;
a. Battery terminals are clean and tight.
b. All component connections and grounding connections are clean and tight.
c. The master switch is “ON” unless using a tester with its own power supply such as ohmmeter
which must never be connected to battery voltage.
d. That the key start switch is in the proper position when checking a circuit that receives its power
through this switch. Refer to the wiring diagram.
WARNING! Avoid accidental engine starting. Tag the cab panel to alert other
personnel that work is being performed on the machine with the master switch in
position “ON”.
COMPLAINT
PROBABLE CAUSE REMEDY
Engine will not Crank or Crank Slowly
1. Weak batteries Check the condition of each battery. Refer to
”Testing and Maintenance the Battery” in this
Section
2. Dirty or loose power cable connections Clean all connections and tighten
3. Defective starting switch, 10[A] circuit
breaker, start-up lock switch,
cranking motor solenoid switch, cranking
motor, master switch
By process of elimination, check for voltage
using a voltmeter or check lamp, beginning at
the power source and step by step until problem
is found. Refer to Starting Circuit in Paragraph 3
in this Section
Transmission Control Malfunction
1. Gears and ranges cannot be changed. Limp
home mode inoperative.
Damaged: Drive train lock solenoid valve or its
relay or proximity switch.
Refer to Wiring Diagram.
2. Gears and ranges cannot be changed. Limp
home mode operative.
Refer to Electronic Controller Operation After
Power Up above
3. Electrical problem in direction or range drive
circuit
Refer to Drive Train Control Circuit in Paragraph
3 in this Section and to Drive Train Control
System above in this Section.
4. Hydraulic or mechanical problem in
transmission or valves
Refer to “SERVICE DIAGNOSIS” in SECTION 7
“DRIVE TRAIN” and to SECTION 7C
“TRANSMISSION”
Cooling Systems Fan Control Malfunction
1. Electrical problem in fan control circuit Refer to Fan Circuit in Paragraph 3 in this
Section
2. Problem in fan drive system Refer to “SERVICE DIAGNOSIS” in SECTION
10 “HYDRAULIC”
NOTE: For electrical switches location on the machine refer to their system.