Circuit/System Testing

Ignition OFF, all vehicle systems OFF. Disconnect the KR98 Vehicle Level Control Compressor Relay It may take up to 2 min for all vehicle systems to power down.
Ignition ON, verify a test lamp illuminates between the KR98 Vehicle Level Control Compressor Relay terminal 87 and ground.
- If the test lamp does not illuminate and the circuit fuse is good
1. Ignition OFF.
2. Test for less than 2 Ω in the B+ circuit end to end.
  - If 2 Ω or greater, repair the open/high resistance in the circuit.
  - If less than 2 Ω, verify the fuse is not open and there is voltage at the fuse.
- If the test lamp foes not illuminate and the circuit fuse is open
1. Ignition OFF.
2. Test for infinite resistance between the B+ circuit and ground.
  - If less than infinite resistance, repair the short to ground on the circuit.
  - If infinite resistance
3. Disconnect the harness connector at the G3 Air Suspension Compressor.
4. Test for infinite resistance between the control circuit terminal 30 and ground.
  - If less than infinite resistance, repair the short to ground on the circuit.
  - If infinite resistance, replace the G3 Air Suspension Compressor.
- If the test lamp illuminates
Momentarily install a 30 A fused jumper wire between the B+ circuit terminal 87 and the control circuit terminal 30.
Verify the G3 Air Suspension Compressor is activated.
- If the G3 Air Suspension Compressor does not activate
1. Disconnect the harness connector at the G3 Air Suspension Compressor.
2. Test for less than 2 Ω in the control circuit end to end.
  - If greater than 2 Ω, repair the open/high resistance in the circuit.
  - If less than 2 Ω, replace the G3 Air Suspension Compressor.
- If the G3 Air Suspension Compressor activates
Replace the KR98 Vehicle Level Control Compressor Relay.