Electrical System

Type:
12 volt, negative earth

BX 16v Fuse Coding

Mark/Ampere rating/Colour Protected circuits

F1/10/Red:
Engine cooling fan relay coil, coolant level indicator unit, oil level control unit, tachometer, reversing lights, coolant temperature control unit

F2/25/White:
Air blower (and ventilation system), instrument panel.

F3/25/White:
Heater fan speed control lighting, instrument panel lighting, stop-lights, cigar lighter, on-board computer, heated rear screen relay coil, rear wash/wipe, windscreen wash/wipe (and timer), “door not locked” symbol lighting (and warning lights), electric window relay coil, rear view mirror, sunroof, front seat spotlight, interior light timer unit.

F4/30/Green:
Engine cooling fan

F5/10/Red:
Hazard warning lights

F6/30/Green:
Electric rear windows

F7/30/Green:
Glovebox lighting, on-board computer (+ direct supply), cigar lighter, supply socket, door locking, roof light and timer unit, boot lighting, radio electrical supply

F8/20/White:
Horn, heated rear screen

F9/30/Green:
Electric window control unit

F10/5/Brown:
Rear fog lights and warning light

F11/5/Brown:
RH tail light

F12/5/Brown:
LH tail light, rear number plate lights

F13/5/Brown:
Side and tail warning lights, sidelights, switch lighting, on board computer lighting, front fog light switch (and warning light, relay coil)

F14/10/Red*:
Hydraulic unit for ABS
*May be 25 amp White on later models

General information

The electrical system is of the 12 volt negative earth type and comprises a 12 volt battery of which the negative terminal is earthed, an alternator which is driven from the crankshaft pulley, a starter motor and related electrical accessories, components and wiring.

The battery supplies a steady amount of current for the ignition, lighting and other electrical circuits and provides a reserve of electricity when the current consumed by the electrical equipment exceeds that being produced by the alternator.

The alternator is controlled by a regulator. This ensures a high output if the battery is in a low state of charge or the demand from the electrical equipment is high. Alternatively, it ensures a low output if the battery is fully charged and there is little demand for the electrical equipment.

An on-board computer system is fitted to some BX 16v models, being located in the floor console forward of the gear lever. This system has fifteen possible functions, the main ones being to log petrol consumption, average speed, journey time elapsed and the estimated time of arrival, plus the range possible on the remaining fuel. The main system components are the computer unit, the distance sensor and the fuel output sensor.

All models are equipped with a dim-dip lighting system to comply with UK regulations. The function of the system is to prevent the vehicle being driven with only the sidelights illuminated. This system uses a relay-controlled resistor circuit. When the sidelights are on (ignition also on), the headlights are automatically illuminated at approximately one-sixth their normal dipped beam power.

Further details of the system are available in the Downloads section which features pages from the Technical Manuals.