Troubleshooting Hints

PERFORM BEFORE BEGINNING SYSTEM DIAGNOSIS
1. Check the RH rear junction block HDLP circuit breaker for continuity. if open, check for a short to ground in CKT 1740 (ORN).
2. Check the IF fuse block TMNSS Fuse by visual inspection. If open, check for a short to ground in CKT 139 (PNK).
3. For Buick, check the IF fuse block IGN 1 Fuse by visual inspection. If open, check for a short to ground in CKT 39 (PNK).
4. For Oldsmobile, check the engine compartment junction block FOG LAMP Fuse by visual inspection If open. check for a short to ground in CKT 42 (RED).
5. If one headlight does not work, check the bulb. the connections, and the related wiring (see schematic).
6. If the headlights on one side are dim, check the ground on that side, Check the suspect headlamp assembly connector for proper cavity contact.
7. Check that grounds G103, G104, and G202 are clean and tight.
8. For Buick, if the headlights and park lights do not light when the keyless entry transmitter is operated. check for an open in CKT 624 (BLK/WHT). If OK. refer to Keyless Entry. Keyless Entry
9. Before component replacement, check for poor connections at related component and in-line harness connector cavity connections.
10. Check for broken (or partially broken) wire inside of the insulation which could cause a system malfunction but prove good in a continuity/voltage check with a system disconnected. These circuits may be intermittent or resistive when loaded. and if possible, should be checked by monitoring for a voltage drop with the system operational (under load).
11. Check for proper installation of aftermarket electronic equipment which may affect the integrity of other systems.