Lull 944E-42 Service Manual - Manual (Page 645)

9.135 Model 644E-42/944E-42 Rev. 6/04
Electrical System
With the ignition ON, the
worklight switch OFF and
the turn signal control
selector rotated to the 1st
(Position Parking Lights
Only) and pulled back for
flash high beams, high
beams remain OFF.
Not
OK
Check for
battery voltage at pin 2,
wire [WL1A] (RED/WHT)
on worklight switch.
If OK
Replace turn signal control.
If OK
Replace cab
roadlight harness.
Not
OK
With worklight switch OFF,
check for battery
voltage at pin 1, wire
[WLHB] (DK BLU/ORG)
on worklight switch.
Replace worklight switch.
Not
OK
Check for battery voltage
at pin 1, wire
[WLHB] (DK BLU/ORG)
at turn signal control.
Replace cab
roadlight harness.
If OK
Before troubleshooting any
electrical circuit, ALWAYS begin
by checking the following:
1. Fuses.
2. All connections relating to
circuit are clean and tight.
3. All grounding straps are intact
and securely fastened, refer to
Section 9.1.12, “General
Overview (Vehicle Ground
Strap Locations).”
4. Verify that the low beam
headlight circuit is operating.
If not, follow the steps listed
at, Section 9.8.41, “Light
Power Relay Circuit &
Troubleshooting (Option),”
before troubleshooting the
flash high beam circuit.
5. Verify that the high beam
headlight circuit is operating.
If not, follow the steps listed
at, Section 9.8.42, “Roadlight
High Beam Circuit &
Troubleshooting (Option),”
before troubleshooting the
flash high beam circuit.
6. If one of the high beams work,
the circuit is fine, the failed
bulb needs to be replaced.
7. High beam flash DOES NOT
operate if worklight switch is in
the ON position.