LEMON Manuals: Even more car manuals for everyone
Home >> Lincoln >> 1991 >> Town Car Cartier >> Repair and Diagnosis >> Accessories & Equipment >> Gauges & Instrument Panels >> Instrument Panel - Electronic >> Testing >> Pinpoint Tests >> Test AL, Outside Temperature Always Reads -40°F (-40°C)

Test AL, Outside Temperature Always Reads -40°F (-40°C)

  1. Verifying Condition: Turn ignition on. Read outside temperature. Remove No. 1 fuse (15-amp) from fuse panel below instrument panel, left of steering column. Fuse is in lower right corner of fuse panel. Instrument cluster should go blank.
  2. After 30 seconds, reinstall fuse and read outside temperature. If reading is correct, refer to pinpoint index for further testing. See Figure . If reading is incorrect, proceed to step 3).
  3. Checking Air Temperature Sensor Connector: Disconnect electrical connector from air temperature sensor at radiator support. Air temperature sensor contains a Brown connector with Dark Blue/Yellow and Pink/Orange wires.
  4. Connect jumper wire between air temperature sensor wiring harness terminals. Turn ignition on. Remove No. 1 fuse (15-amp) from fuse panel, reinstall after 30 seconds and read outside air temperature.
  5. If reading is 135-140°F (57-60°C), proceed to step 10). If reading is-40°F (-40°C), proceed to step 6).
  6. Checking Connector: Disconnect 16-pin Black connector at left rear corner of engine compartment at rear of wheel well. Turn ignition on. Remove No. 1 fuse (15-amp) from fuse panel, reinstall after 30 seconds and read outside air temperature.
  7. If reading is 135-140°F (57-60°C), repair wiring between connector and air temperature sensor. If reading is -40°F (-40°C), proceed to step 8).
  8. Checking Instrument Cluster: Remove instrument cluster finish panel. Connect jumper wire between instrument cluster connector C1, pin No. 1 (Pink/Orange or Black/Light Blue wire) and ground. See Figure .
  9. Turn ignition on. Remove No. 1 fuse (15-amp) from fuse panel, reinstall after 30 seconds and read outside air temperature. If reading is 135-140°F (57-60°C), repair wiring between instrument cluster and C1 connector. If reading is -40°F (-40°C), replace instrument cluster. Install door pillar sticker to indicate instrument cluster has been replaced.
  10. Checking Air Temperature Sensor: Using ohmmeter, measure resistance between air temperature sensor terminals. Resistance should be 33,000-47,000 ohms at 60-70°F (16-21°C). If reading is within specifications, proceed to step 11). If resistance is not within specifications, replace air temperature sensor.
  11. Checking Air Temperature Sensor Connector: Check for defective connections at air temperature sensor. If connections are defective, repair as necessary. If connections are okay, return to step 1), and retest system.
scientia non olet · About LEMON Manuals