Lull 944E-42, Service Manual

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9.125 Model 644E-42/944E-42 Rev. 6/04
Electrical System
With the ignition ON and
the turn signal control
selector rotated to 2nd
position (Position Parking
Lights & Headlights) and
pulled back for low beam
lights ON, low beam lights
remain OFF.
Not
OK
Check for battery voltage at
pin 8, wire [RL1] (RED/WHT)
on turn signal control
selector connector.
Not
OK
Not
OK
If OK
Check for battery voltage at
pin 5 on turn signal control
selector connector.
If OK
Check for battery voltage at
pin 1, wire [LB1B] (RED) or
wire [LB1C] (RED) on
roadlight connector.
Replace turn signal
control selector.
Not
OK
Check for battery voltage at
pin B, wire [LB1] (RED) on
roadlight female connector.
Replace cab
roadlight harness.
If OK
Replace vehicle
roadlight harness.
Replace cab
roadlight harness.
If OK
Replace failed roadlight.
Not
OK
Verify ground at roadlight
connector, pin 6.
If OK
Check for proper ground at
wire [EG7] (BLK) at ground
buss bar.
Not
OK
Clean, tighten and recheck.
If OK
Replace vehicle
roadlight harness.
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 high beam
circuit is operating. If not,
follow the steps listed at,
Section 9.8.41, “Light Power
Relay Circuit &
Troubleshooting (Option),”
before troubleshooting the
low beam lights circuit.
5. If one of the low beams work,
the circuit is fine, the failed
bulb needs to be replaced.