No ground on engine symptoms

An electrical circuit needs a good ground to function properly. Many people ask - why is engine demining necessary? The answer is - poor electrical grounding can affect one or more electrical systems, because it forces the current to look for other simpler paths. This can cause all sorts of problems with lights, sensors, modules and other electrical and electronic components, all of the above is also true to answer the common question - what is the purpose of mass in a car.

What could happen to the car due to poor ground contact?

With the electrical equipment of any vehicle, malfunctions can occur that seem to people far from electricians to be the work of evil spirits.
And the culprit of mysterious malfunctions in the electrical equipment of a motorcycle or car, in most cases, is poor contact of the negative terminals - “ground”. But let's take things in order. Many drivers know that the method of connecting electricity consumers to a power source (generator or battery) on any vehicle is single-wire. The second (negative) wire is the body of a car or the frame of a motorcycle (trike, scooter, ATV, etc.). The very idea of connecting the negative side of a power source (battery) to a steel frame or body is quite old and natural, as it can significantly simplify, lighten and reduce the cost of any vehicle.

A separate ground wire is used to connect the engine to the body or frame, since the engine hangs on rubber mounts that do not allow current to pass through, while both plus and minus are required by the starter, and, for example, by the carburetor solenoid valve. On foreign cars, especially injection ones, there may be even more consumers requiring electricity (and, accordingly, plus and minus). But the positive wires usually begin and end with quite reliable terminals, which are usually in completely sealed plastic blocks or rubber covers, but the negative wires are attached to the body or frame according to the principle “some water will find a hole.” And the body itself, in the place where the hole is drilled and the negative wire is secured, begins to rust very quickly, unless, of course, appropriate measures are taken immediately.

In addition, many do not take into account another important fact, which is known even to a novice electrician: aluminum and copper terminals cannot be connected to each other, since these metals, to put it mildly, are “not friendly” with each other, and begin to oxidize intensively. How can oxidized parts have normal contact? But I often see on the vehicles of inexperienced drivers, on the aluminum housing of the gearbox or engine head, a screwed-on copper terminal of the negative wire, which, in addition, is also washed by streams of water in bad weather.

A steel body or frame is also not friendly with copper, like aluminum, and forms an electrochemical couple. And the saddest thing about this is that the steel in such a connection will be blown away by two people and will corrode several times faster. As a result, the contact disappears (or there is a significant loss of current). Standard terminals installed at the factory are usually tinned. But under a thin layer of tin, which is easy to tear off when installing the terminal, there is still the same copper alloy.

Based on the above, it is obvious that the negative connections themselves to the body or frame are initially less reliable than the copper wires themselves and their copper terminals (tips). Now imagine, for example, in order for electricity to reach the carburetor solenoid valve, the electric current must go along a copper wire (copper bus) from the battery to the body, then along another wire to the engine, then along the intake manifold studs and their threads, often coated with sealant (or the studs are rusty), and finally go along the threads of the solenoid valve itself. Loss of contact in any of the listed places - and the circuit is open, and hence a whole bunch of malfunctions. As a result, the inexperienced driver is surprised - why did the carburetor suddenly begin to work poorly and gasoline consumption increase? You need to go to a carburetor specialist or buy another carburetor. But usually few people know that in such a situation the carburetor has nothing to do with it. And I gave one example of a sudden malfunction, but there can be many of them.

Therefore, in modern cars or motorcycles, full-fledged negative wires are increasingly used, because modern on-board electronics will not work without them, and most devices or programs will fail. On such equipment, reliable contact is especially important. Experienced electricians know, and I have already said this: in electrics there are only two faults - there is a contact where it is not needed, and there is no contact where it is needed.

Typical malfunctions on a car due to poor ground contact (but not all, we read about the rest below) .

These malfunctions, as I already said, seem like miracles to inexperienced drivers. It is not uncommon at a factory (especially a domestic one) to place the negative terminal of the headlight on a stud or bolt securing the headlight housing to the body, and then tighten it with a nut. At first glance, many will think that everything is correct, because the stud or fastening bolt is welded to the body. But the headlight housing is made of soft plastic, and the nut on the terminal cannot be tightened properly, otherwise the plastic will crack. In the end, it only takes a short drive on our roads to weaken such contact to the point of its complete absence. But in a standard headlight with a modest lamp of 55-60 watts, the current consumed even by such a lamp is quite large - up to 10 amperes (if both its threads are energized, both high and low beam).

In the end, a bad contact, if it does not disappear completely, will burn out, the resistance of such a connection will increase even more, and from a school physics course we know that the greater the resistance, the more heat is released when current passes in this place. This means that the burning of contacts will intensify even more (a vicious circle), and it’s not far from a fire (plastic burns well). And many young novice drivers, instead of a standard 50-60 watt lamp, install a hundred (100 watt), which consumes even more current. The consequences can be dire.

.3.3. Poor Ground Detection

The negative terminal of the battery is connected to “ground” - the metal of the body, engine or gearbox; Moreover, many elements of electrical equipment are connected in such a way that only the positive wire is suitable for them, while the current returns to the battery through the metal of the body. This means that the electrical component mount and the body are part of the electrical circuit. As a result, poor or corroded fasteners can cause the element to fail or cause it to perform erratically or poorly. In particular, light bulbs may glow dimly (especially if the light bulb's ground point is connected to another electrical component that is still on), electric motors may run slowly, and the operation of one circuit may have a seemingly unnoticeable effect on the operation of another circuit.

Don't forget that many vehicles use ground wires between certain components such as the engine/transmission and the body, that is, in areas where there is no direct metal-to-metal contact due to soft rubber mounts or a layer of paint.

To check the reliability of the element's grounding, it is necessary to disconnect the battery and connect one of the ohmmeter probes to a reliably grounded element. Connect another probe to the wire or connection to the body that needs to be checked. The resistance shown by the ohmmeter should be zero; if not, check the connection as follows.

If you suspect there is no ground, disassemble the connection and clean the body area and wire terminal (or the grounding surface of the element) to bare metal. Carefully remove all traces of dirt, then use a knife to remove all paint so that there is reliable contact between the two metal surfaces.

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When assembling, tighten the connector securely; When connecting a wire terminal, install a serrated washer between the terminal and the body surface to ensure a secure connection. When connecting, prevent future corrosion by applying a layer of Vaseline or silicone grease.

Why is mass needed in a car?

Grounding the engine provides an electrical return path for the starter. Poor engine grounding is a common problem resulting in hard starting and no starting.

The following test takes a voltage drop reading to determine any unwanted resistance in the motor ground circuit.

Disconnect the ignition or fuel system to prevent engine starting during testing.

If the ignition system has a distributor, you can disconnect the high voltage cable from the distributor cap and ground it to the engine (bolt or bracket) using a jumper wire. On other systems, you may be able to remove the fuel pump fuse. Consult your vehicle's owner's manual or vehicle repair manual to locate the fuse. You can also use a remote starter switch. Connect the switch to the starter relay or solenoid (selector relay) control circuit terminals.

Set the DMM to a constant voltage and select a range as close as possible but greater than the battery voltage. For example, 20 volts. Or select the auto-ranging feature, depending on your multimeter's features.
Connect the red meter lead to a clean surface of the engine and the black meter lead to the negative (-) terminal of the battery.
Have a helper run the engine for about five seconds, this is enough to get a good current reading.

You should get a reading of 0.2 volts or less. If necessary, refer to your manufacturer's specifications in your vehicle's repair manual. Did you get a higher reading? There is unwanted resistance in the ground circuit. To find the problem, proceed to the following steps.

Move the red lead of your meter to the main ground terminal on the engine side.
Have a helper crank the engine while you take a voltage drop reading.

Repeat the previous two steps, moving the red wire to the connector connecting the black main ground wire to the battery terminal. When you get a reading around 0.2V or lower, the unwanted resistance is between this and the previous test point. Check for corrosion, broken or loose wires.

Where is the mass of the Chevrolet Niva engine?

But if everything is in order with the relay, and the devices do not work, then there may be a problem elsewhere - the mass attachment point. The negative wire coming out of the battery is connected to the car body and goes to some of the main energy consumers in the form of wires. This is sometimes the difficulty when calling an electrician.

The architecture of the circuit can be described as follows: a wiring harness comes out of the negative terminal, connecting devices operating from one ground point, then wires connecting other ground points are connected to them using a crimp sleeve. As a result, finding a specific mass attachment point is quite difficult.

For example, the mass of the mirror control unit is located behind the trunk trim. But with the engine everything is a little simpler. Since it is connected to the frame and body through pads, which are essentially a dielectric, it has its own wiring harness. The terminals are located on the left side of the engine, below the ignition module. They are responsible for the operation of the ECU and ECM sensors.

Engine demining and signs of poor grounding

Solutions to the problem

If power outages occur frequently or current leakage occurs during long periods of parking, you can improve the system to solve the problem. It’s not difficult to get the job done; the minimum set of tools that every motorist should have is enough. The procedure depends on the nature of the malfunction.

How to make mass better

If removing and cleaning the contacts does not produce any effect, you will have to use more radical repair methods. In some models, the problem with a minus on the body is a real “disease”, so it is necessary to improve the design in order to eliminate the manufacturer’s shortcomings:

It is necessary to monitor the condition of the wires and replace them if there is even the slightest doubt about reliability. It is best to use the same elements as those installed, plus high-quality fasteners.

Installing the mains switch

The switch will protect the car from current leakage, short circuit, and can also serve as an additional anti-theft system. It’s easy to install it yourself; most often, one of two options is used:

The switch is not suitable for cars with an alarm and central locking, since if there is no ground, the system will not work. It is also undesirable to install it on models with a lot of electronics.

It is not difficult to locate the ground wires; they should be periodically removed and processed to ensure good contact. When checking, it is better to use a multimeter, this is the easiest way to detect damage if it is present. It is recommended to replace worn wires in a timely manner, and to prevent leaks, you can install a power switch button.

ABS sensor

It is checked by two parameters: voltage and resistance.

To start measuring, select the appropriate mode on the multimeter. If you want to know the resistance value, for most the norm is 1.2-1.8 kOhm. Connect the device to the sensor and start taking measurements. At the same time, shake the wires going to the element. If the numbers on the screen change and become higher or lower than normal, there is a problem with the sensor.

Measuring voltage is a little more difficult - this can only be done with a jack or in a car service on a stand. You need to spin the car wheel to 40-50 rpm and monitor the multimeter readings. On any machine it should output 2 volts.

Where is the ignition relay located on a Niva Chevrolet?

The ignition relay is located in the passenger compartment fuse box; it can be found on the driver's side of the instrument panel, opposite the seat. On the diagram it is usually designated K6 and in the technical description it is sometimes called an addition relay.

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It is responsible for turning on the fuel pump and supplying voltage to other elements. Triggered when the ignition key is turned. At this moment, you can hear a click behind the instrument panel. This electric coil built into the relay receives voltage and closes the contacts of a certain circuit. If there is no characteristic sound when turning the key, this may indicate its failure.

ADDITIONAL MASS WIRES

If the weight of the engine with the body is bad, then problems arise:

When symptoms of poor engine weight appear, there is a way out of the unpleasant situation - in this case, additional weight on the engine will help. You can install an additional wire in different ways, the most important thing is that it reliably connects the car body with the power unit. For example, one end of the wire can be attached to the stud of the upper shock absorber support, and the other to the stud of the intake manifold of the internal combustion engine. It is important that the wire has a large cross-section, preferably no less than that of the bulk itself.

On new machines, problems with mass wires rarely occur. But on older models, the body studs rust. Finding a lack of ground is not so easy, so car owners use the installation of additional wires. So the additional mass on the generator helps eliminate battery charging leakage.