Jeep Cherokee 2000 Service Manual - page 455
CONDITION
POSSIBLE CAUSES
CORRECTION
FOG LAMPS FLASH
RANDOMLY
1. Poor lighting circuit Z1-ground.
1. Test for voltage drop across Z1-ground
locations. Refer to Group 8W.
2. High resistance in fog lamp circuit.
2. Test amperage draw of fog lamp circuit.
3. Faulty fog lamp switch.
3. Replace fog lamp switch.
4. Loose or corroded terminals or
splices in circuit.
4. Inspect and repair all connectors and
splices. Refer to Group 8W.
FOG LAMPS DO NOT
ILLUMINATE
1. Blown fuse for fog lamp.
1. Replace fuse. Refer to Group 8W.
2. No Z1-ground at fog lamps.
2. Repair circuit ground. Refer to Group
8W.
3. Faulty fog lamp switch.
3. Replace fog lamp switch.
4. Broken connector terminal or wire
splice in fog lamp circuit.
4. Repair connector terminal or wire splice.
5. Defective or burned out bulb.
5. Replace bulb.
HEADLAMP DELAY MODULE
DELAY FUNCTION INOPERATIVE
(1) Ensure headlamps operate before proceeding.
(2) Remove, inspect and test the HDLP delay 10
amp fuse in junction box. Replace if defective.
(3) With the key off and the connector discon-
nected, measure the resistance from the delay mod-
ule connector, terminal 4 to vehicle body ground. The
ohmmeter should indicate zero ohms. If not, repair
the open circuit in the wire harness to vehicle body
ground.
(4) With the key on measure the voltage between
the delay module connector, terminal 8 and vehicle
body ground. The voltmeter should indicate battery
voltage. If not, repair the open circuit in the wire
harness from ignition switch to HDLP delay module.
(5) Turn headlamps on and measure voltage at
delay module connector, terminal 6. The voltmeter
should indicate battery voltage. If not repair open cir-
cuit between L2 and HDLP delay module.
(6) Measure the voltage between the delay module
connector, terminal 2 and vehicle body ground. The
voltmeter should indicate battery voltage. If not,
repair the open circuit in the wire harness to the
HDLP fuse in the PDC.
(7) If steps 1 through 6 prove out good, replace
headlamp delay module.
XJ
LAMPS
8L - 5
DIAGNOSIS AND TESTING (Continued)