Toyota Corolla

1992-1998 of release

Repair and operation of the car

Toyota Corolla
+ 1. Maintenance instruction
+ 2. Maintenance
+ 3. Engines
+ 4. Cooling systems, heating
+ 5. Fuel, exhaust systems
+ 6. System of decrease in toxicity
+ 7. Transmissions
+ 8. Coupling and half shafts
+ 9. Brake system
+ 10. Suspension bracket and steering
+ 11. Body
- 12. Electric equipment
   12.1. Safety locks
   12.2. The burned-through crossing points
   12.3. Automatic switches
   12.4. Relay
   12.5. Breakers of indexes of turns / alarm system
   12.6. The combined switch
   12.7. The switches installed on a steering column
   12.8. Lock of ignition and drum of the lock
   12.9. Switch of a heater of back glass
   12.10. Heater of back glass
   12.11. Radio receiver and loudspeakers
   12.12. Antenna
   12.13. Bulbs of headlights of head light
   12.14. Headlights of head light
   12.15. Replacement of bulbs
   12.16. System of day inclusion of headlights
   12.17. Engine of screen wipers
   12.18. Instrument guard
   12.19. Sound signal
   12.20. System cruise control
   12.21. System of the central lock
   12.22. System of window regulators
   12.23. Rear-view mirrors with the electric drive
   12.24. Safety airbag
   + 12.25. Electroschemes

12. Electric equipment


The system of electric equipment has working voltage of 12 Volts and uses negative grounding. Food for headlights and all other elements of electric equipment arrives from the lead-acid accumulator which is recharged from the generator.

In this chapter operations of repair and service for various elements of electric equipment which are not connected with the engine are described.

It is necessary to notice that during the work with system of electric equipment it is necessary to disconnect a wire of the negative plug of the accumulator for prevention of short circuit and / or ignition.


If the stereoplayer of your car has system of the coding, check, whether you know a code of activation of the player before an accumulator detachment.

Detection of malfunctions in system of electric equipment

The typical electric chain consists of an element of electric equipment, switches, the relay, engines, safety locks, the burned-through crossing points or automatic switches and wires and connections which connect all elements among themselves and connect them to the accumulator and mass of the car. To simplify process of troubleshooting in the end of this chapter electric circuits of system of electric equipment of the car are given.

Before check of a faulty chain, study the schematic diagram of this chain in the beginning to understand of what elements it consists. The source of malfunction can be found quicker if to define what of elements of this chain work normally. If some elements or chains fail at once, the problem probably consists in the fused safety lock or bad grounding as often one safety lock is responsible for some chains.

Problems with work of system of electric equipment are usually caused by the simple reasons, such as the oxidized or unreliable contacts, the fused safety lock, the fused burned-through crossing point or the faulty relay. Visually check a condition of all safety locks, wires (if it is possible) and connections in a faulty chain before check of other elements of this chain. If you are going to use instrumentations, use schematic diagrams to define, what connections need to be checked for failure detection.

The main devices necessary for search of malfunction in an electric equipment chain, are the voltmeter (or a bulb on 12 Volts with connecting wires), the device for check of integrity of chains, the accumulator with connecting wires and a cap wire, it is desirable with the automatic switch which can be used for parallel connection to a chain. Before search of malfunction with use of the control and measuring equipment, study schematic diagrams to define connection points.


An inspection of tension needs to be carried out if the electric chain is faulty. Connect one of probes of a control bulb to the negative plug of the accumulator or mass of the car. Connect the second probe to connection in the checked chain, it is desirable located as it is possible closer to the accumulator or a safety lock. If the control bulb lights up, tension is present: it means that the part of a chain between connection and the accumulator is serviceable. Continue check of other part of a chain in the same way. When you find a point where tension is absent, it means that the source of malfunction lies between this point and the last point where tension was present. The majority of problems is caused by bad connection.


Do not forget that tension is only present at some chains if to turn a key in the ignition lock in a certain situation.


One of methods of search of a point of short circuit consists in getting a safety lock and to connect a control bulb or the voltmeter to plugs of connection of a safety lock when all other elements of electric equipment of this chain are switched off. In a chain there should not be tension. Move wires here and there and watch a control bulb. If it lights up, so somewhere in this area short-circuits one of wires, it is probable in that place where isolation was wiped. The same test can be carried out on any other element of a chain, including the switch.


Carry out an inspection of reliability of grounding to check reliability of connection of an element of electric equipment to the mass of the car. Disconnect the accumulator and connect one of device wires for check of integrity of chains to the mass of the car. Connect the second wire to connection or a point of grounding which is subject to check. If the control bulb lights up, so grounding as it should be.


Check of integrity of a chain is necessary to define, whether is not present in a gap chain. Disconnect tension from a chain and check a chain for integrity by means of a bulb with the connected power supply. Connect bulb wires to the ends of a chain (or by the positive end and mass of the car); if the control bulb lights up, in a chain there are no gaps. If the bulb does not light up, so somewhere in a chain there is a gap. In the same way it is possible to check the switch, having connected a control bulb to switch plugs. After turning on of the switch, the control bulb has to light up.


Visually to find not closed chain happens rather difficult as it is often difficult to notice the oxidized or bad connection of contacts. It is sometimes rather simple to move a wire of connection or a wire in a plait of wires to eliminate this malfunction. Unreliable work of elements of electric equipment is also often caused by the oxidized or bad connection.

Finding of malfunction in system of electric equipment is represented rather simple operation if to understand that work of system of electric equipment is based that current flows from the accumulator through wires, switches, the relay, safety locks and the burned-through crossing points to electric equipment elements (a bulb, the engine, etc.) and on the mass of the car, from where it comes back to the accumulator. Any malfunction in system of electric equipment represents a hindrance during current from the accumulator or to the accumulator.