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Home >> Chevrolet >> 2020 >> Express 2500 LS, 6.0L Eng VIN G >> Repair and Diagnosis >> External Pages >> Different car >> Section 83 (Fixed And MOVEABLE Windows) >> Diagnostic Information and Procedures >> Rear Window Defogger Malfunction >> Component Testing

Component Testing

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Relay Test

  1. Ignition OFF, disconnect the KR5 Rear Defogger Relay.
  2. Test for 60-180 Ω between terminals 85 and 86.
    • If less than 60 Ω or greater than 180 Ω 

      Replace the KR5 Rear Defogger Relay.

    • Go to next step: If between 60-180 Ω 
  3. Test for infinite resistance between the terminals listed below:
    • 30 and 86
    • 30 and 87
    • 30 and 85
    • 85 and 87
    • If less than infinite resistance 

      Replace the KR5 Rear Defogger Relay.

    • Go to next step: If infinite resistance 
  4. Install a 3 A fused jumper wire between relay terminal 85 and 12 V. Install a jumper wire between relay terminal 86 and ground.
  5. Test for less than 2 Ω between terminals 30 and 87.
    • If 2 Ω or greater 

      Replace the KR5 Rear Defogger Relay.

    • Go to next step: If less than 2 Ω 
  6. All OK