LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 1985 >> Corvette Standard >> Repair and Diagnosis >> Accessories & Equipment >> Gauges & Instrument Panels >> Instrument Panel - Electronic >> Testing >> Speedometer Diagnosis

Speedometer Diagnosis

  1. Visually examine transmission sensor connector to make sure it is not loose, corroded or otherwise defective. If not okay, replace, clean or tighten connector as required. If okay, disconnect speedometer sensor harness at PM generator.
  2. Connect speedometer harness to signal generator (J-33431) connector, turn tester on and set signal switch to 54 MPH. Check that speedometer reads 52-56 MPH.
  3. If okay, replace PM generator. Recheck for operative speedometer and odometer modules. If not okay, go to step 4).
  4. If in step 2), speedometer did not read 52-56 MPH and odometer did not turn, go to step 5). If odometer turned but speedometer did not work, replace cluster. If speedometer read 52-56 MPH, but odometer did not turn, go to step 6).
  5. Remove cluster from vehicle and visually check harness and cluster printed circuit for opens or shorts in wiring. Check voltages and resistances. See VOLTAGE AND RESISTANCE CHECK charts. If okay, replace cluster. If not okay, replace wiring or printed circuit and check for operational speedometer and odometer.
  6. Check for loose wiring connection between odometer motor terminals and cluster. If connection is not loose or broken, connect signal generator odometer connector to odometer motor lead. Turn tester on. If odometer motor works, replace cluster. If not, replace odometer motor.
scientia non olet · About LEMON Manuals