Diagnostics of malfunctions of electrical equipment (Honda CB 400 SF, 1 generation, 1992-1999) [Information for owner: Maintenance]

Malfunction	Fault definition	Cause of malfunction	Remedy
When the ignition key is turned to the ON position, the oil pressure warning lamp does not light up	Use a multimeter to check if the lamp is working	Control lamp burnt out	Replace the lamp
	Check that the fuse is working properly	Ignition system fuse blown	Replace the fuse
	Check the cleanliness and tightness of the wires at the battery terminals and at the fuse and ignition switch contacts	No contact at battery terminals	Clean and restore wire connections
Sound signal does not work	Check the contacts on the horn connector, check the horn with a multimeter	The sound signal is faulty, the wires of the sound signal are broken, the sound signal terminals are oxidized	Check the cleanliness of the contacts in the signal terminal connector, steering switch block, replace the horn
When the ignition key is turned to the ON position, the oil pressure warning light comes on, but the engine does not start	Check the battery charge, inspect its terminals and ignition coil terminals	There is no contact at the terminals of the wires of the ignition coil, there is no contact at the terminals of the engine control unit	Charge the battery, restore the contacts on the terminals of the ignition coil and the engine control unit
When the ignition key is turned to the ON position, the headlight lamp does not light	Check the condition of the fuses	Headlight circuit fuse blown	Replace the fuse
	Check your contacts	No contact at ignition switch terminals	Check and repair contact at the ignition switch connectors
	Visually	Burnt out headlight bulb	Replace headlight bulb
When the ignition key is turned to the ON position, the rear position lamp does not light up	Check the condition of the fuses	The fuse has blown, one of the lamp bulbs has burned out, the lamp wires have broken	Replace lamp bulbs, repair wire breaks
When the turn signal is on, the indicators do not light up	Check the condition of the fuses	Turn signal circuit fuse blown, turn signal relay internal fault	Replace the fuse, replace the relay if necessary
When the engine is running, the oil pressure warning lamp lights up steadily	Check for oil in the engine	Internal malfunction of the oil pressure sensor, no oil in the engine, faulty oil pump	If there is enough oil in the engine, it is necessary to check the operation of the oil pump and the oil pressure sensor; replace if necessary

Diagnostics of malfunctions of electrical equipment (Honda CB400SF/1)