- Garry's Mustang Help
COURTESY LAMPS
INOPERATIVE
- AA1 CHECK FUSE FOR VOLTAGE
- Using a test lamp, check the output side of fuse 8 (10A) for volts
- - Did test lamp illuminate?
- Yes
- GO TO AA3
- No
- GO TO AA2
- AA2 CHECK CIRCUIT FOR SHORT
- - Remove fuse 8 (10A)
- - Connect one lead of an ohmeter to a known good ground, connect second lead to output side of fuse 8 (10A). Measure Resistance.
- - Is resistance 5 ohms or less?
- Yes
- SERVICE, Circuit 54 (LG/Y) for short to ground. Restore vehicle. RETEST system. REPLACE fuse 8 (10A).
- No
- GO to AA3
- AA3 CHECK VOLTAGE AT SWITCHES
- -Remove courtesy lamp switch (13713) at each door (4005A26). (If sedan, remove courtesy lamp switch at rear door (24631) also.) Leave courtesy lamp switch connected to harness.
- - Using a test lamp connected to a known good ground, check Circuit 54 (LG/Y) for voltage at each courtesy lamp switch.
- - Is voltage present at all courtesy lamp switches?
- Yes
- GO TO AA4
- No
- SERVICE Circuit 54(LG/Y) at suspect courtesy lamp switch for open circuit. RESTORE vehicle. RETEST system.
- AA4 CHECK COURTESY LAMP SWITCHES
- - Disconnect courtesy lamp switches.
- - Using an ohmeter, check for continuity at all switch terminals of each courtesy lamp switch.
- - Is there continuity?
- Yes
- GO TO AA5
- No
- REPLACE courtesy lamp switch. RESTORE vehicle. RETEST system.
- AA5 CHECK HEADLAMP SWITCH SUPPLY
- - Remove headlamp switch. Leave headlamp switch connected
- - Using voltmeter, test terminal D1 Circuit 54(LG/Y) for voltage.
- - Is voltage present?
- Yes
- GO TO AA6
- No
- SERVICE Circuit 54(LG/Y) for open circuit. RESTORE vehicle. RETEST system.
- AA6 CHECK HEADLAMP SWITCH OUTPUT
- - Remove voltmeter from terminal D1 and connect it to terminal D2 Circuit 706(GY).
- - Turn headlamp switch couterclockwise to the stop.
- - Is voltage present?
- Yes
- SERVICE Circuit 53(BK/BL) for open. RESTORE vehicle. RETEST system.
- No
- REPLACE headlamp switch. RESTORE vehicle. RETEST system.
- Garry's Mustang Help
CHARGE INDICATOR
FAULTY
- E1- LAMP CHECK NO.1
- Engine OFF, Key in OFF position.
- - Is charge indicator on?
- Yes
- Refer to Section 14-00 SERVICE as necessary
- No
- Go to E2.
- E2- LAMP CHECK NO.2
- Engine OFF, Key in RUN position.
- - Is charge indicator on?
- E3- LAMP CHECK NO.3
- Key in RUN position, Engine RUNNING
- - Is charge indicator on?
- Yes
- Go to E6
- No
- Lamp test complete and operational.
- E4- INOPERATIVE INDICATOR LAMP
- Key in ON position, Engine OFF
- Disconnect regulator connector and ground "I" terminal.
- - Is charge indicator on?
- Yes
- REFER to Section 14-02. SERVICE as necessary.
- No
- Go to E5.
- E5- CHECK CIRCUIT 904(LG/R) FOR OPEN
- Turn ignition switch to the OFF position. Engine OFF
- Remove instrument cluster.
- Using an ohmmeter connected to a known good ground, connect second lead to pin 10 Circuit 904(LG/R).
- Measure resistance.
- - Is resistance 5 ohms or less?
- Yes
- REMOVE jumper wire. Go to E6.
- No
- SERVICE circuit 904(LG/R) for open circuit. RESTORE vehicle. RETEST system.
- E6- CHECK CIRCUIT 904(LG/R) FOR SHORT
- Disconnect instrument cluster connectors.
- Disconnect voltage regulator connector.
- Using an ohmmeter connected to a known good ground, connect second lead to pin 10 Circuit 904(LG/R).
- Measure resistance.
- - Is resistance 5 ohms or less?
- Yes
- SERVICE circuit 904(LG/R) for open circuit. RESTORE vehicle. RETEST system.
- No
- Go to E7.
- E7- CHECK CIRCUIT16(R/LG) FOR VOLTAGE
- Turn ignition switch to the RUN position.
- Using a test lamp connectec to a known good ground, connect other end to pin 11 circuit 16(R/LG).
- - Did test lamp illuminate?
- Yes
- Go to E8.
- No
- SERVICE circuit 16(R/LG) for open circuit. RESTORE vehicle. RETEST system.
- E8- CHECK CHARGE INDICATOR LAMP
- Remove charge indicator lamp bulb.
- Using an ohmmeter, check continuity of bulb
- - Is bulb continuity OK?
- Yes
- REPLACE instrument cluster printed circuit. RESTORE vehicle. RETEST system.
- No
- REPLACE damaged bulb. RESTORE vehicle. RETEST system.