Component Testing

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.

   • 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.

   • 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.

   • If less than 2 Ω 
6. All OK

Rear Defogger Grid Test

NOTE:

Lightly touch the grid lines when testing with the test lamp. If the test lamp point is scraped through the grid line it can cause an open in the circuit

1. Engine running, command the Rear Defogger ON with a scan tool.
2. Verify that a test lamp illuminates between each rear window defogger grid line and ground. The test lamp should be off when testing at the ground side of the grid and get brighter as the test lamp moves closer to the voltage supply side of the grid. The test lamp should be dim when testing each grid line in the middle
   • If the test lamp remains bright at the middle of the grid line. 

     The grid line is open between the test point and the ground side of the grid.

     Replace the rear window

   • If the test lamp remains off at the middle of the grid line. 

     The grid line is open between the test point and the voltage supply side of the grid.

     Replace the rear window

   • If the test lamp remains dim at the middle of each grid line. 
3. All OK