14.2.3. Check of reliability of grounding

The negative plug of the accumulator is connected to (mass) of the car – to metal of the engine / transmission and a body of the car – and the majority of systems of electric equipment are developed so that one feeding wire approached an element of electric equipment only, and current came back through car body metal.

It means that fastening of an element of electric equipment and a body of the car are a part of an electric chain.

Therefore, the bad or oxidized fastening can be the reason of a large number of malfunctions in system of electric equipment, from a full exit of a chain out of operation before its unreliable work.

In particular, bulbs can dimly burn (especially if other chain using the same grounding is included), engines (for example, engines of screen wipers or the fan of cooling of a radiator) can slowly work and inclusion of any chain can influence work of other chain.

Notice that on many cars the connecting grounding strips between various units of the car, for example, between the engine / transmission and a body are used, usually when between elements there is no metal contact because of use of rubber fastenings, etc.

1. Disconnect the accumulator and connect one of ohmmeter probes to (mass) of the car.
2. Connect the second probe to a wire or a point of grounding which needs to be checked. Resistance registered by an ohmmeter has to equal to zero; if is not present, check connection as follows.
3. If you consider that connection not as it should be, investigate connection and smooth out a contact surface and the plug of a wire or a surface of the grounded element to pure metal.
4. Remove completely dirt and traces of corrosion, then, by means of a knife remove a paint coat to receive reliable compound of metal with metal.
5. At assembly, reliably record connection; at installation of the plug of a wire, use gear washers between the plug and a body.
6. After connection, for prevention of formation of corrosion apply a layer of vaseline or silicone lubricant on connection or process it sealant, such as (Holts Damp Start) or water-repellent lubricant, such as (Holts Wet Start).