TM  10-3930-669-20 1.  DRIVE AXLE OVERHEATING (CONT). KNOWN INFO Engine temperature 105°F or over. Glow plug indicator operates. Parking brake OK. Brake fluid OK. Drive axle oil level correct. Master cylinder OK. Drive axle OK. Axle oil pump ground wire OK. Axle oil pump OK. Relay R8 ground wire OK. Wire 29 to relay R8 OK. Wire 74 OK. Relay R8 OK. Wire 29 to drive axle temperature switch OK. Drive axle oil temperature switch OK. Wire 72 OK. Drive axle oil cooler ground wire OK. Wire 29 to engine temperature switch OK. Engine temperature switch OK. Wire 71 OK. Relay R7 ground wire OK. Wire 29 to relay R7 OK. POSSIBLE PROBLEMS Wire 73 faulty. Relay R7 faulty. TEST OPTIONS Continuity test. STEICE-R # 1. REASON FOR QUESTION If continuity is not present, wire 73 is faulty.  If wire 73 is OK, relay R7 is faulty. 2-356