Despite this, most generators can be brought back to life. Overhauled, restored, updated - call it what you like - a generator is a quite common phenomenon. There are two ways in which it can be "born" again.
The first is when an old assembly is steam cleaned or simply rinsed and then painted on the outside and sold as refurbished, often with "guarantee" substitutions, in most cases expressed by the phrase: "If it doesn't work, bring it back". Whether such a generator will fail in a month or later is unknown.
The second way is to buy a really restored unit. They are of good quality, as they have been completely disassembled, cleaned, checked, and defective and questionable parts have been replaced.
Factory rebuilt alternators go through a much similar restoration process, with small parts such as brushes, slip rings and bearings being replaced without fail. A factory refurbished unit is as good as new and, with the same warranties, has a lifespan close to that of a new unit.
In the latter case, the generators are tested for maximum load and power. You get what you pay for. Repainted generators are usually significantly cheaper than quality repainted nodes. Of course, you can purchase a repair kit, but if your generator case is faulty, then you have no choice.
On the way to replacing the generator
Manufacturers' application and replacement tables are usually accurate, but some firms install alternators of various brands and sizes on their machines. Even if the old and new alternators look the same at first glance, be sure to check the electrical connectors, maximum load current, mounting brackets, pulley attachments, and mounting plane to pulley distance - to ensure that the alternator pulley will be in the same plane as the pulleys on the crankshaft and water pump.
Sometimes, despite the fact that the node looks a little different, its operation is possible. Despite the difference "origin", generators most often have the same maximum load current and are made so that all attachment points and connections are in the same places.
Pulley, key and nut may not be included in the repair kit. Then they are moved from the old node to the new one.
You also need to find out what caused the generator to fail. If the cause is external, then the installed spare parts may just as well fail. Today we will talk about the most common malfunctions of generators.
We repair ourselves
In addition to replacing the unit, there are other ways to solve the problems mentioned above. For example, many people replace alternators when the brushes are in poor contact, although this problem can be fixed with a simple cleaning.
The first way is to clean the brushes yourself and for free. Even if you need spare parts, this option will be the cheapest. It is not as complicated as it seems at first glance. If you fail, you will not be in a worse position than before.
The second way is to contact a specialist to check and repair a faulty generator. It is difficult to predict what the cost of repairs will cost. It depends on the nature of the fault, the required spare parts and their cost. In any case, your cost will be approximately half the cost of a factory rebuilt unit but less than half the cost of a new generator - the savings will be significant.
However, in each of these situations, the age of the generator must be taken into account, as well as the economic feasibility of replacing one or two parts (brushes or slip rings), if others are likely to fail soon. For non-standard or expensive generators, replacement of parts is preferable, but it makes sense to replace the most common models as a whole.
Generator malfunctions
Probably the very first symptom is an abnormal operation of the battery charge indicator lamp. If it does not light up at all, then the cause of this may be a malfunction of the lamp itself or its power circuit. To find out, disconnect the alternator, turn on the ignition, and use a test light to determine if the circuit on the small connector is good. The small connector may be labeled Ind, Ign, D+, or 15. If both the test lamp and the indicator lamp are on, then the lamp supply circuit is good. If the generator does not produce a charging current, then the brushes are probably faulty. However, if neither the control lamp nor the indicator lamp comes on during the test, the lamp itself and its power circuit should be checked.
When the test lamp does not go out during normal engine operation, the malfunction is most likely in the generator itself. True, a short circuit in the section of the circuit between the control lamp and the generator gives the same result.
Also check with a tester for voltage at the large alternator connector. It should always be here - if it is not there, then check the connection of the generator to the battery. If the voltage regulator on your car is located separately from the alternator, then it may also be faulty. In this case, it is better to remove the alternator and voltage regulator and contact an auto electrician.
The simplest test of the generator load current is as follows: turn on the side lights of the car and start the engine. If the lights do not start to burn brighter when the engine is running, then this is the best evidence that the generator is not producing current. If you have a voltmeter, connect it to the battery terminals and start the engine. At increased cold-running speeds, the generator should produce current, and the voltmeter should show about 14 V. Do the readings differ by more than 1 V? Either the alternator or the voltage regulator is faulty.
In many cases, the constant chasing of the control light indicates a malfunction of the generator, but malfunctions are possible in another place, and the generator, paradoxically, at this time can be serviceable.
And yet, for most car owners, the control light is the only indicator of the health of the generator. The most common causes of abnormal functioning of the charge indicator lamp and typical situations are shown in the table. For example, the line "The control lamp does not light up" implies that the ignition must already be on, and at the same time it does not mean that the engine must be started. Generator malfunctions are listed in order of increasing probability of their occurrence. Faults in italics are not directly related to the generator. Below is a table explaining what some of the above problems can lead to.