Lull 944E-42 Service Manual - Manual (Page 663)

9.153 Model 644E-42/944E-42 Rev. 6/04
Electrical System
9.10.5 Engine Tachometer & Hourmeter Indicator Troubleshooting
If
OK
Not
OK
0000000
RPM X 100
5
10
15
30
20
25
F
1/2
E 104
176
80
248
120 °C
°F
r/min
D
With the park brake ON and
the engine running, check
pin 6, wire [D2] (ORG), for
6.8 to 7.2 volts to dash
panel connector.
Hourmeter indicator
does not register
operating hours.
Check sensor harness male
connector pin A,
wire [AW1] (ORG) for
6.8 to 7.2 volts
Repair/replace
vehicle
sensor harness.
If
OK
If OK
Hourmeter
Indicator
MU4340
Repair/replace cab
harness.
Replace alternator.
Not
OK
Engine tachometer
is not giving a
reading when the
engine is operating.
Engine
Tachometer
Does hourmeter
indicator register
operating hours?
Yes
No
Replace front dash panel.
Does hourmeter
indicator register
operating hours?
Is the engine
tachometer giving a
reading when engine
is operating?
Yes
No
Replace front dash panel.
Check alternator terminal
“B+”, wires [AB1] (RED)
and [AB2] (RED) for
battery voltage.
Check alternator terminal
“W”, wire [AW1] (ORG) for
6.8 to 7.2 volts.
Not
OK
Replace alternator.
If OK
Check alternator
ground wires
[AG1] (BLK) and
[AG2] (BLK).
If OK
Not
OK
Before troubleshooting any
electrical circuit, ALWAYS begin
by checking the following:
1. Fuses.
2. Battery for proper charge.
3. All connections relating to
circuit are clean and tight.
4. All grounding straps are intact
and securely fastened, refer to
Section 9.1.12, “General
Overview (Vehicle Ground
Strap Locations).”