Fuses and relays box diagram Opel/Vauxhall Astra H Fuse box located. Fuse box in engine compartment. The fuse box is at the front left side of the engine compartment. Fuse box diagram Astra H. legend. Fuse layout, version A Several protect some functions fuses. No. Circuit. Fuse box in luggage compartment Astra H. Fuse and relay box diagram Opel/Vauxhall Astra G Fuse box diagram (Astra G since 2001). fuses and relays are coded as follows. R1 . R2. Horn relay. R3. Headlamp high beam relay. R4. Rear screen wiper relay. R5. Door mirror heater relay. R6. Fuse and relay box in the engine compartment Astra G. located. fuse box diagram. early models. late models.