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Test B, Keypad Illumination

This test checks keyless entry module, keypad and related circuits.

  1. Check voltage between pin No. 13 of Brown connector and pin No. 14 of Gray connector and ground. If readings are 10 volts or more, go to step 2). If readings are less than 10 volts, repair open or short in corresponding circuit(s). If necessary, replace burned-out fuses. Repeat QUICK TEST  .
  2. Check continuity between pin No. 2 of Brown connector and pins No. 5 and 6 of Gray connector and ground. See KEYLESS ENTRY MODULE CONNECTOR TERMINAL IDENTIFICATION in TEST A. If continuity exists, go to step 3). If no continuity exists, repair open in corresponding circuit(s) and repeat QUICK TEST  .
  3. Disconnect keypad and Brown module connector. Check continuity between pin No. 1 of Brown connector and ground. If continuity exists, repair short in circuit No. 66 and repeat QUICK TEST  . If no continuity exists, go to steps 4) and 5).
  4. On Town Car, connect keypad connector, but leave Brown connector disconnected. Apply 12 volts between pin No. 1 of Brown connector and ground. If keypad illuminates, go to PINPOINT TEST C. If keypad does not illuminate, go to step 6).
  5. On Mark VII, connect keypad. Apply 12 volts between pin No. 1 (ground) and pin No. 8 of keypad connector. If keypad does not illuminate, replace keypad and repeat QUICK TEST  . If keypad illuminates, go to step 6). See KEYPAD CONNECTOR TERMINAL IDENTIFICATION illustration. On Town Car, disconnect keypad. Check resistance between pins No. 3 and 6 of the keypad connector. If reading is 10 ohms or more, replace keypad. If reading is less than 10 ohms, go to step 6).
  6. On Mark VII, disconnect Gray connector. On Town Car, disconnect Brown connector. Disconnect keypad connector. On Mark VII, check continuity between pin No. 1 of Gray connector (Brown connector on Town Car) and pin No. 7 (or pin No. 3 on Town Car) of keypad harness connector. If no continuity exists, repair open in circuit No. 66 (Light Blue wire) and repeat QUICK TEST. If continuity exists, go to next step.
  7. Disconnect keypad connector. Check for continuity between pin No. 3 (Mark VII), pin No. 6 (Town Car) of keypad and ground. If no continuity exists, repair open in ground circuit to keypad and repeat QUICK TEST. If continuity exists, go to next step.
  8. On Mark VII, check for short between pin No. 12 of Gray connector (Brown connector on Town Car) and ground. If short is found, repair circuit 124 (Brown wire) and repeat QUICK TEST  . If no short is found, go to next step.
  9. On Mark VII, check continuity between pin No. 12 of Gray connector (Brown connector on Town Car) and pin No. 8 (Mark VII), or pin No. 5 (Town Car) of keypad connector. If continuity exists, replace keyless entry module and repeat QUICK TEST  . If no continuity exists, repair circuit No. 124 (Brown wire) and repeat QUICK TEST  .
Fig 1: Keypad Connector Terminal Identification
G90C14474
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