Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1998 GMC Forward Control 6.5 FFACTORY OEM SERVICE PROCEDURE
Electrical Component Locator: Grounds
GROUNDS LOCATION
| Component | Component Location |
|---|---|
| G100 (Commercial Van) | Approximately, 18 cm from breakout to left glow plugs. |
| G100 (Motor Home) | Near left front light breakout, body builder installed. |
| G101 (Commercial Van) | Approximately, 23 cm from breakout to right headlights. |
| G101 (Motor Home) | By right front light breakout. |
| G102 (Commercial Van) | Approximately, 102 cm from breakout harness for right headlights |
| G102 (Motor Home) (A/T) | At rear of left cylinder head. |
| G102 (Motor Home) (M/T) | Near generator bracket. |
| G103 (Commercial Van) (6.5L VIN F) | Approximately, 18 cm from breakout to left glow plugs. |
| G103 (Commercial Van) (7.4L VIN J) | Approximately, 10 cm from breakout to generator. |
| G104 (Commercial Van) (6.5L VIN F) | At rear of left cylinder head. |
| G104 (Commercial Van) (7.4L VIN J) | Approximately, 35 cm from breakout to ignition coil. |
| G104 (Motor Home) | At rear of left cylinder head. |
| G105 (Commercial Van) | At rear of right cylinder head. |
| G105 (Motor Home) | At rear of left cylinder head. |
| G106 (Commercial Van) | Braided strap, at left rear of engine. |
| G106 (Motor Home) | At rear of left cylinder head. |
| G107 (Commercial Van) | Front frame crossmember. |
| G107 (Motor Home) | At rear of left cylinder head. |
| G110 (Commercial Van) | On left frame rail, above steering gearbox. |
| G110 (Motor Home) | Above steering gearbox. |
| G200 (Commercial Van) | On top of steering column support plate. |
| G200 (Motor Home) | Near relay bracket. |
| G201 | On mounting stud of dimmer switch. |
| G202 | On mounting stud of dimmer switch. |
| G350 | At right frame rail, behind transmission. |
| G400 | At left frame rail, in front of fuel tank. |
| G401 | Body builder located. |
Factory Service Tools
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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