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Mercedes Alternator Problems

Essentially an alternator is an electro-mechanical device. This is meant to convert the mechanical energy to electrical energy in the form of alternating current. Generally alternators use a rotating magnetic field with a stationary armature. Sometimes, a rotating armature is used with a stationary magnetic field. Alternators used in automobiles are small rotating machines driven by automotive and other internal combustion engines. They are used to charge the battery and power the electrical system while the engine is operating.

To understand more about a few common problems faced with the Mercedes Benz alternators, below are a few questions answered by Experts.

Is there cause for concern that while working on an Mercedes alternator, coolant accidently entered the oil dipstick area when one of the coolant hoses were disconnected?

Normally coolant in the oil area through the dipstick tube can be detrimental. However if it is a relatively small amount (a few drops) which has entered the oil there may not be any issue. It is highly unlikely a substantial amount (more than an ounce) could have entered the dipstick tube. To be on the safer side it would probably be a good idea to drain the crankcase.

It is suspected a Mercedes 190E’s (1993 model) has an alternator problem, what is the approximate cost to repair this issue?

Although parts and labor rates can vary across different regions, typically a standardized labor rate can be estimated around $100 per hour. The cost of an original Mercedes Benz alternator would be over $500 however, most shops may allow a discount up to the $350 range. This is because the cost of a re-manufactured Bosch alternator is approximately $350. The labor hours involved to test the charging system and to replace the Mercedes alternator would be approximately 1.5 hours. If testing is not involved and if it is a straightforward Mercedes alternator replacement, the labor time required would be one hour.

What could be wrong, the battery and alternator light appear twice on the Mercedes display when it was started and the car is difficult to start the car is hard to start.

The first step to take in this case is to ensure the battery is normal. If need be it can be charged properly and completely using a battery charger. Next while the engine is cranked, using a multimeter, the voltage needs to be checked to see if it drops below 10 volts. If it does, the battery may need to be replaced. If it is clear the battery is fine but could have discharged, hence the Mercedes alternator should be checked. The role of the Mercedes alternator is to charge the battery with 14 volts. This voltage should not drop below 13.5 volts even if there are additional components using the Mercedes alternator. The voltage regulator on the Mercedes Benz alternator could be old and therefore malfunctioning when the engine is started. This can result in the warning light appearing.

How can one ascertain whether there is a problem with the Mercedes alternator?

Prior to attempting Mercedes alternator troubleshooting, the battery of the car needs to be charged, tested and replaced if necessary. In case the battery is faulty, the Mercedes alternator output is automatically low. To begin with, in case the there are no warnings being displayed on the vehicle screen, most probably the Mercedes alternator is fine. This is because generally Mercedes alternator problems are alerted by the vehicle’s computer. To test the alternator, the car should be connected to a charging system tester to measure the Mercedes alternator output. The alternator should also be checked for any faulty diodes. It should be noted, using a radar detector to measure voltage can be unreliable.

What would cause the 300CE 1990 model Mercedes to start without issue but there is an odd sound and the heater/cooling fans work intermittently?

I If there is an odd sound most likely the alternator bearings could be failing. To confirm the problem, the serpentine belt would need to be removed. This is to allow the Mercedes alternator and other rotating components to be turned by hand to identify the defective component.

Mercedes Benz alternator problems can be many and sometimes an unrelated problem can affect the functioning of the Mercedes alternator. There can be times when Mercedes alternator replacement is required. In such a case, one could be looking for advice, second opinions or information on the process or system. At this juncture a knowledgeable person such as an Expert can be helpful to guide in a step-by-step manner or provide with important and useful information.
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