Mercedes Multi Purpose Relay - Meyle 2105400072

Product Information

A multi-purpose relay is an electrical switch that uses a small electrical current to control a larger current electrical circuit. The function of a relay is to activate various systems or functions that use a high electrical current without requiring high-current wiring directly running through the switchgear or ECU. The relay consists of a coil and a set of contacts. When a small current energizes the coil on the low current side, it creates a magnetic field that flips the switch back and forth, closing or opening the contacts and completing or breaking the circuit that powers the high-amperage device.

Multi-purpose relays are generalized relays that can run a number of different types of systems, such as fuel pumps, cooling fans, lighting, HVAC components, and windshield wipers just to name a few. This is why you will notice a multi-purpose relay may be listed for several different applications within a car, or the same application across multiple vehicles.

To diagnose a relay, you can energize the low current side using a basic 12v signal. You will hear the relay clicking. If the click is inconsistent or dulled, it might not be making a good contact. When it clicks, a multimeter should show continuity and near-zero resistance between the high-current contacts. If not, then the relay may be bad. Basic multi-purpose relays are very simple devices, so they don’t usually fail. However, if the relay has been subjected to extreme temperatures, or weather exposure, or is very old, never rule out a bad relay causing problems in your electrical system.

• System Failure: Several systems use multi-purpose relays to power them. When a relay goes bad, those systems will intermittently work or fail. A proper electrical diagnosis with a multimeter, or swapping the relay with a known good one is the best way to fix a failed relay.

About Meyle

Meyle Original Parts

The MEYLE ORIGINAL range comprises over 21,000 OE-compliant spare parts for almost all current passenger cars and vans – quality-tested, robust, durable and proven a thousandfold on the roads of the world You can find the parts you need safely and without any mix-ups here and will get them in next to no time thanks to a high level of availability.

The economical alternative to almost all servicing and repairs.

All MEYLE ORIGINAL parts completely comply with the required MEYLE specifications of the vehicle manufacturers and are guaranteed to fit exactly like the original. They score points with their excellent value for money, MEYLE’s high level of quality and tried-and-tested source materials.

First choice for professionals and people with high expectations.

Especially when it comes to the IAM and demanding gearheads, MEYLE ORIGINAL spare parts are an ideal choice to carry out repair and maintenance work professionally, economically and to a high standard! Therefore, MEYLE ORIGINAL spare parts are the first choice when it comes to keeping a vehicle in good working order economically – after all, MEYLE is the ‘driver’s best friend’ and as reliable as a good friend no matter what.