Section 17-02: Lighting, Interior
1994 Mustang Workshop Manual
DIAGNOSIS AND TESTING

Pinpoint Tests—Illuminated Entry

  

PINPOINT TEST B: ILLUMINATED ENTRY SYSTEM NOT OPERATING CORRECTLY

 

B1 CHECK FUSE 8 (10A) FOR VOLTAGE

Yes
GO to B3.

No
GO to B2.

 

B2 CHECK CIRCUIT 54 (LG/Y) FOR SHORT

Yes
SERVICE Circuit 54 (LG/Y) for short to ground. RESTORE vehicle. RETEST system. REPLACE fuse 8 (10A).

No
GO to B3.

 

B3 CHECK CIRCUIT 54 (LG/Y) AT ILLUMINATED ENTRY MODULE

  • Gain access to illuminating entry actuator .
  • Using a voltmeter, check for voltage at Pin 8 Circuit 54 (LG/Y) at illuminating entry actuator .
  • Is voltage present?
Yes
GO to B4.

No
SERVICE Circuit 54 (LG/Y) for open circuit. RESTORE vehicle. RETEST system.

 

B4 CHECK CIRCUIT 57(BK)

  • Using an ohmmeter connected to a known good ground, connect second lead to Pin 1 Circuit 57 (BK) at illuminating entry actuator . Measure resistance.
  • Is resistance 5 ohms or less?
Yes
GO to B5.

No
SERVICE Circuit 57 (BK) for open circuit. RESTORE vehicle. RETEST system.

 

B5 CHECK CIRCUIT 465 (W/LB)

  • Disconnect illuminating entry actuator .
  • Using an ohmmeter connected to a known good ground, connect second lead to Pin 2 Circuit 465 (W/LB) at illuminating entry actuator connector.
  • Measure resistance.
  • Is resistance 5 ohms or less?
Yes
GO to B6. Leave ohmmeter connected.

No
Leave ohmmeter connected. GO to B8.

 

B6 CHECK CIRCUIT 465 (W/LB) FOR SHORT

  • Gain access to LH interior lamp switch .
  • Disconnect LH interior lamp switch .
  • Measure resistance.
  • Is resistance 5 ohms or less?
Yes
GO to B7. Leave ohmmeter connected.

No
REPLACE damaged LH door interior lamp switch . RESTORE vehicle. RETEST system.

 

B7 CHECK CIRCUIT 465 (W/LB) AT RIGHT INTERIOR LAMP SWITCH

  • Gain access to RH door interior lamp switch .
  • Disconnect RH door interior lamp switch .
  • Measure resistance.
  • Is resistance 5 ohms or less.
Yes
SERVICE Circuit 465 (W/LB) for a short to ground. RESTORE vehicle. RETEST system.

No
REPLACE damaged RH door interior lamp switch . RESTORE vehicle. RETEST system.

 

B8 CHECK LEFT DOOR INTERIOR LAMP SWITCH

  • With ohmmeter still attached, raise LH door handle and hold.
  • Read resistance.
  • Is resistance 5 ohms or less?
Yes
Leave ohmmeter connected. GO to B10.

No
Leave ohmmeter connected. GO to B9.

 

B9 CHECK LEFT INTERIOR LAMP SWITCH CIRCUITRY

  • Gain access to LH door interior lamp switch .
  • Disconnect left door interior lamp switch .
  • Using a jumper wire, connected to a known good ground, connect other end to Circuit 465 (W/LB) at door interior lamp switch connector.
  • Read resistance.
  • Is resistance 5 ohms or less?
Yes
REPLACE damaged LH door interior lamp switch . RESTORE vehicle. RETEST system.

No
SERVICE Circuit 465 (W/LB) for open circuit. RESTORE vehicle. RETEST system.

 

B10 CHECK RIGHT INTERIOR LAMP SWITCH

  • With ohmmeter still attached, raise RH door handle and hold.
  • Read resistance.
  • Is resistance 5 ohms or less?
Yes
GO to B12.

No
Leave ohmmeter connected. GO to B11.

 

B11 CHECK RIGHT INTERIOR LAMP SWITCH CIRCUITRY

  • Gain access to door interior lamp switch .
  • Disconnect door interior lamp switch .
  • Using a jumper wire connected to a known good ground, connect other end to Circuit 465 (W/LB) at interior lamp switch connector.
  • Read resistance.
  • Is resistance 5 ohms or less?
Yes
REPLACE damaged RH door interior lamp switch . RESTORE vehicle. RETEST system.

No
SERVICE Circuit 465 (W/LB) for open circuit. RESTORE vehicle. RETEST system.

 

B12 CHECK CIRCUIT 298 (P/O)

  • Turn the ignition switch to the RUN position.
  • Using a voltmeter, check Circuit 298 (P/O) at illuminating entry actuator connector Pin 7 for voltage.
  • Is voltage present?
Yes
GO to B15.

No
GO to B13.

 

B13 CHECK CIRCUIT 298 (P/O) SUPPLY

  • Using a voltmeter, check Circuit 298 (P/O) for voltage at fuse 1 (15A).
  • Is voltage present?
Yes
SERVICE Circuit 298 (P/O) for open circuit. RESTORE vehicle. RETEST system.

No
GO to B14.

 

B14 CHECK FUSE 1 (15A)

  • Using voltmeter, check for supply voltage to fuse 1 (15A).
  • Is voltage present?
Yes
REPLACE fuse. GO to B15.

No
SERVICE Circuit 687 (GY/Y) for open circuit. RESTORE vehicle. RETEST system.

 

B15 CHECK CIRCUIT 53 (BK/LB)

  • Connect voltmeter to Pin 6, Circuit 53 (BK/LB) at module connector.
  • Raise either door handle and read voltage.
  • Is voltage present?
Yes
System functional. If courtesy lamps do not illuminate, go to courtesy lamp test in this Section.

No
REPLACE damaged illuminating entry actuator . RESTORE vehicle. RETEST system.