Component Tests and General Diagnostics

1. Disconnect front axle switch at front axle.
2. Ensure 4WD indicator lamp is on, then disconnect front axle switch connector.
3. If 4WD lamp stays on, then transfer case switch and front axle switch are satisfactory.
4. Disconnect electronic synchronizer connector from transfer case.
5. Connect test lamp from wiring harness connector to ground. If test lamp lights, proceed to step 6. If test lamp does not light, proceed as follows:
a. Check transfer case relay, replace if necessary.
b. Check circuit for an open, repair or replace as necessary.
c. If transfer case relay and circuit are satisfactory, replace clutch coil relay.
6. Check synchronizer coil for continuity. If continuity is not indicated, replace clutch coil. If continuity is indicated, clutch coil is satisfactory.
7. Check fluid levels and linkage adjustments before determining synchronizer to be faulty.