Lull 944E-42 Service Manual - Manual (Page 662)

Electrical System
9.152 Model 644E-42/944E-42 Rev. 6/04
9.10.4 Engine Air Filter Restriction Warning Indicator Troubleshooting
MU4400
Check air filter element.
Check for plugged or dirty
condition. Check air inlet for
obstruction
Engine air filter
restriction warning
indicator stays ON
while operating.
Repair as needed.
Disconnect harness at air filter
pressure switch. Indicator light
should go out.
If OK
Repair as needed.
Replace air filter pressure
switch and retest system.
If OK
If OK
Check circuit for grounded
wire [D12A] (YEL/ORG).
If grounded, repair wire.
Refer to page 9.48 or 9.50.
Replace dash panel.
If circuit tests 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
Engine Air Filter
Restriction
Warning Indicator
Check connections and
circuits at air filter pressure
switch on air cleaner
assembly.
Not
OK
Not
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).”
5. Check dash panel bulbs for
proper function.