Car electrical relays
More informationAt Global Parts, we offer a wide selection of original used car parts, including relays for many popular car brands such as BMW, Mini, Mercedes, Audi, Volkswagen, and others. The relays we offer undergo quality control to ensure you receive a top-quality product.
Make
Category
Subcategory
Condition
In Stock
Price
-5%
Part no. 6901469
BMW E60 E87 E90 F10 F30 Relay Electrical Unit Black 4 Pin Tyco 6901469
Promo price
PLN 51.95
PLN 49.35
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 6980177
BMW X1 X3 X5 X6 Z4 Z8 Relay Changeover Function Green 6980177
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 1472984
Mini R50 R52 R53 R55 R56 R57 R58 R59 R60 R61 5-Pin Black Relay Wiper 1472984
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 8373700
BMW E60 E63 E87 E90 E91 Relay Make Contact White Green 8373700
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 1388911
BMW E36 E38 E21 E85 R52 R57 Change-Over Contact Relay Violet 1388911
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
Part no. 8200308271
Fuse Pink Mercedes W415 Citroen Renault Kangoo Trafic Relay 4-Pin 8200308271
PLN 46.95
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 6915327
BMW E46 E39 E60 E81 E87 E90 E91 F10 F20 F30 Relay Make Contact Sky Blue 6915327
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 1742690
BMW E60 E63 E87 E90 Relay Changer Make Contact Salmon Red 1742690
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 9207913
BMW F20 F21 F22 F30 F31 F32 F33 F36 G30 Fan Motor Relay 9207913
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 9198302
BMW F10 F11 F20 F21 F30 F31 130A Electric Fan Motor Relay 9198302
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 1393415
BMW 3 5 7 Series E36 E38 E90 E91 F10 F11 Change-Over Contact Relay Grey 1393415
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 6977982
Mini Cooper R50 R56 R57 R60 Relay No Contact Taubenblau 6977982
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 4H0951253C
Seat Skoda Audi VW Polo 6R Multi Use Control Module Relay 4 Pin 646 4H0951253C
Promo price
PLN 42.95
PLN 40.80
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 1378238
BMW E60 E63 E87 E90 E91 Relay Make Contact Orange 1378238
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. A0025428319
Mercedes W176 W204 C207 W212 C218 W246 Relay 4-Pin Black Hella 12V A0025428319
Promo price
PLN 42.95
PLN 40.80
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 3D0951253A
VW Volkswagen Audi Seat Skoda Relay Black 5 Pins 12V 50A Set 433 3D0951253A
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. A0035422819
Battery Relay Mercedes W176 W246 W447 Cut Off Module Control Unit A0035422819
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 6G9T-14B192-EA
Ford Fiesta Transit Relay 4-Pin Grey FoMoCo Unit 6G9T-14B192-EA
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. A0025421419
Mercedes W163 W169 W203 W210 Relay 5-Pin Yellow TYCO A0025421419
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 7M0951253C
Volkswagen T5 Audi Seat Skoda Relay Black Control Unit 5 Pin 12V 7M0951253C
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 6G9T-14B192-EA-1
Ford Fiesta Transit Relay 4-Pin Grey FoMoCo Unit 6G9T-14B192-EA SET X2
Promo price
PLN 42.95
PLN 40.80
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 6G9T-14B192-BA
Ford Galaxy Mondeo Transit Relay 4-Pin Black FoMoCo Unit 6G9T-14B192-BA
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 8T2T-14B192-AB
Ford Mustang GT Mk6 Main Power Relay 4 Pins 8T2T-14B192-AB
Promo price
PLN 42.95
PLN 40.80
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 8K0951253
Audi VW Volkswagen Seat Relay 643 Unit Module 4 Pins 8K0951253
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 8373700-1
BMW E60 E63 E87 E90 E91 2X Relay Make Contact White Green Set 8373700
Promo price
PLN 47.95
PLN 45.55
Delivery: Aug 13
If paid before 14:00
-15%
Part no. 8373700-3
BMW E60 E63 E87 E90 E91 5X Relay Make Contact White Green Set 8373700
Promo price
PLN 61.95
PLN 52.66
Free delivery: Aug 13
If paid before 14:00
-5%
Part no. A0025422619-1
Relay Mercedes W203 W204 W212 W639 W906 4-Pin Grey Hella 12V A0025422619
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 4H0951253A
Seat Skoda Audi VW Polo 6R Multi Use Control Module Relay 4 Pin 645 4H0951253A
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
Part no. 5M5T-14B192-EA
Ford Transit Custom Grey Relay 12V 70A 4 Pin ++165271F 5M5T-14B192-EA
PLN 46.95
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 8366625
BMW 259 259R 259 R22 Connection Plug Relay Pink Tyco 8366625
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. A0035421619-1
Mercedes W177 Relay 052 Fuse Box Relay Slot B D E 70A Tyco SET X2 A0035421619
Promo price
PLN 42.95
PLN 40.80
Delivery: Aug 13
If paid before 14:00
-15%
Part no. 7640508-2
BMW 1 3 4 Series F20 F21 F30 F31 F32 F33 Cooling Fan Control Unit Radiator
Promo price
PLN 84.95
PLN 72.21
Free delivery: Aug 13
If paid before 14:00
-5%
Part no. A0025422619-3
Relay Mercedes W203 W204 W212 W639 W906 4-Pin Grey Hella 12V A0025422619
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 1472984-2
Mini R50 R52 R53 R55 R56 R57 R58 R59 R60 5-Pin Black Relay Wiper Set 1472984
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 8D0951253A
Audi A6 C6 Multi Use Relay Unit Module 4 Pins 373 8D0951253A
Promo price
PLN 42.95
PLN 40.80
Delivery: Aug 13
If paid before 14:00
-5%
Part no. A0009822923
Mercedes W177 W205 W247 Relay Fuse Unit Module 4 Pins Grey A0009822923
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 431951253G
Audi S8 A8 D3 Relay Control Module Unit Purple 381 4 Pins 431951253G
Promo price
PLN 42.95
PLN 40.80
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 1472984-3
Mini R50 R52 R53 R55 R56 R57 R58 R59 R60 5-Pin Black Relay Wiper Set 1472984
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. A0035420819
Mercedes W176 W205 W213 W242 W447 W907 Relay 4-Pin Black Tyco Unit A0035420819
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. A0035421619
Mercedes W177 Relay 052 Engine Fuse Box Relay Slot B D E 70A Tyco A0035421619
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. GX73-12B533-AD
Range Rover Evoque L538 Glow Plug Relay Module 2.0 GX73-12B533-AD
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. PEO118811
Mazda 6 GJ Relay 4-Pin Electrical Unit Multi-Purpose Relay Black ACVN51212
Promo price
PLN 42.95
PLN 40.80
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 6977982-2
Mini Cooper R50 R53 R56 R57 R60 Relay No Contact Taubenblau Blue Set 2X 6977982
Promo price
PLN 42.95
PLN 40.80
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 038907281D
Genuine VW Audi Seat Skoda Diesel Glow Plug Relay Unit Black 9 Pins 038907281D
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 6G9T-14B192-CA
Ford Fiesta Transit Relay 4-Pin Black FoMoCo Unit 6G9T-14B192-CA
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 5M5T14B192CA
Ford Transit Custom Relay 4-Pin Black 12V 40A FOMOCO SET 5M5T14B192CA
Promo price
PLN 42.95
PLN 40.80
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 6G9T-14B192-DA
Ford Galaxy Mondeo Transit Relay 4-Pin Black FoMoCo Unit 6G9T-14B192-DA
Promo price
PLN 47.95
PLN 45.55
Delivery: Aug 13
If paid before 14:00
-5%
Part no. A0025428919
Relay Mercedes W176 W246 5-Pin Yellow Hella 12V A0025428919
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 443937105B-1
Volkswagen Audi Skoda Seat Thermal Fuse Relay Amp 15A 12V 443937105B
Promo price
PLN 42.95
PLN 40.80
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 9207913-1
BMW F20 F21 F22 F30 F31 F32 F33 F36 Fan Motor Relay 9207913
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. A0025421219
Mercedes W168 W203 W211 Relay 6-Pin Black Tyco A0025421219
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. A0025421119
Mercedes W163 W168 W203 W211 Relay 4-Pin Black Hella A0025421119
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. A0025428819
Mercedes W176 W246 Relay Current 4 Pin 12V Hella A0025428819
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 6901469-1
2X Relay BMW E60 E87 E90 F10 F30 4 Pin Tyco Set Black 6901469
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 443937105B
VW Volkswagen Audi Skoda Seat Little Fuse Amp 30A 12V 443937105A
Promo price
PLN 42.95
PLN 40.80
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 4H0951253A-2
Seat Skoda Audi VW Polo 6R Multi Use Control Relay 4 Pin 645 4H0951253A SET X3
Promo price
PLN 61.95
PLN 58.85
Free delivery: Aug 13
If paid before 14:00
-5%
Part no. 1J0927841
Audi Volkswagen Seat Skoda ESP Relay Unit Grey 444 1J0927841
Promo price
PLN 42.95
PLN 40.80
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 6G9T-14B192-BA-1
Ford Galaxy Mondeo Transit Relay 4-Pin Black FoMoCo Unit SET X2 6G9T-14B192-BA
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 038907281D-2
VW Volkswagen Caddy 2K Audi A4 B9 Glow Plug Relay Unit Black Diesel 038907281D
Promo price
PLN 42.95
PLN 40.80
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 5M5T14B192AA
Ford Transit Custom Mk8 Relay 4-Pin Black 12V 20A 5M5T-14B192-AA
Promo price
PLN 42.95
PLN 40.80
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 1378238-1
BMW E60 E63 E87 E90 E91 Relay Make Contact Orange Bosch 4 Pins Set 1378238
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 8200587119
Renault Trafic III Vauxhall Vivaro B Relay 5-Pin Grey Unit 8200587119
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. A0025428719
Mercedes W176 W204 W207 W166 Relay 4 Pin Grey Hella A0025428719
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. BU5T-14B192-AA
Ford Focus Mk3 Relay Module 4-Pin Black BU5T-14B192-AA
Promo price
PLN 42.95
PLN 40.80
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 90494959
GM Vauxhall Opel Relay 4-Pin Multi Use Glow Plug Unit Magenta 90494959
Promo price
PLN 47.95
PLN 45.55
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 9367693
BMW M5 F90 G11 G12 Power Distribution Relay Fuse Box Make Contact 9367693
Promo price
PLN 61.95
PLN 58.85
Free delivery: Aug 13
If paid before 14:00
-5%
Part no. DH22-14B192-AA
Land Rover Discovery Sport L550 Relay 4-Pin 20A 12V Unit Black DH22-14B192-AA
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 6836504
BMW F20 F21 LCI F30 F31 F32 F13 Electric Coolant Fan Motor Relay 130A 6836504
Promo price
PLN 94.95
PLN 90.20
Free delivery: Aug 13
If paid before 14:00
-5%
Part no. GU5T-14B192-GA
Ford Transit Mk8 Relay High Power 4-Pin Black FoMoCo GU5T-14B192-GA 4RA933714
Promo price
PLN 42.95
PLN 40.80
Delivery: Aug 13
If paid before 14:00
-15%
Part no. CC1112B533AB
Ford Transit MK7 Diesel Glow Plug Relay Control Unit Module CC11-12B533-AB
Promo price
PLN 94.95
PLN 80.71
Free delivery: Aug 13
If paid before 14:00
Part no. 8D0951253A-1
VW Audi Seat Skoda Multi Use Relay Module 4 Pins 373 Black 12V 40A 8D0951253A
PLN 42.95
Delivery: Aug 13
If paid before 14:00
-5%
Part no. A0025428419
Relay Mercedes W176 W246 4-Pin Black Hella 12V A0025428419
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 8373700-2
BMW E60 E63 E87 E90 E91 4X Relay Make Contact White Green Set 8373700
Promo price
PLN 51.95
PLN 49.35
Delivery: Aug 13
If paid before 14:00
-15%
Part no. 1388911-2
BMW E36 E38 E85 Mini R52 R57 4x Change-Over Contact Relay Violet Set 1388911
Promo price
PLN 61.95
PLN 52.66
Free delivery: Aug 13
If paid before 14:00
-5%
Part no. 5M5T14B192EA
Ford Transit Custom Relay 4-Pin Black 12V 40A FOMOCO 5M5T14B192EA
Promo price
PLN 42.95
PLN 40.80
Delivery: Aug 13
If paid before 14:00
Part no. 2S7T-14B192-AA
Range Rover L322 Black Relay 4-Pin Unit 12V 40A 2S7T-14B192-AA
PLN 46.95
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 1388911-1
BMW E36 E38 E85 Mini R52 R57 2x Change-Over Contact Relay Violet Set 1388911
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 8Z0951253
Skoda Octavia II 5 Pin Black Relay Control Module Unit Set Kit 8Z0951253
Promo price
PLN 42.95
PLN 40.80
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 6915327-1
BMW E46 E60 E81 E87 E90 E91 F10 F20 F30 2x Relay Make Contact Sky Blue 6915327
Promo price
PLN 46.95
PLN 44.60
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 1K0951253-1
VW Volkswagen Audi Seat Relay 449 12V 30A Unit Module 4 Pins 1K0951253
Promo price
PLN 42.95
PLN 40.80
Delivery: Aug 13
If paid before 14:00
-5%
Part no. Q0009857V001
Smart Roadster W452 Heated Seat Control Relay Module 9 Pin Black Q0009857V001
Promo price
PLN 94.95
PLN 90.20
Free delivery: Aug 13
If paid before 14:00
Part no. A0009828523
Mercedes W164 Suspension Compressor Relay A0009828523
PLN 42.95
Delivery: Aug 13
If paid before 14:00
Part no. 11130287
Vauxhall Movano C 4-Pin Relay Unit 12V 50A Omron Black 11130287
PLN 61.95
Free delivery: Aug 13
If paid before 14:00
-5%
Part no. A0035420219-3
Mercedes W639 W906 Relay 5-Pin Control Unit 12A Blue A0035420219
Promo price
PLN 61.95
PLN 58.85
Free delivery: Aug 13
If paid before 14:00
-5%
Part no. 1J0919506M
Volkswagen Skoda Seat Audi Radiator Cooling Fan Relay Control Unit 1J0919506M
Promo price
PLN 42.95
PLN 40.80
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 5M5T-14B192-EA-1
Ford Transit Custom Relay 4-Pin Black 12V 40A FOMOCO Set X2 5M5T-14B192-EA
Promo price
PLN 61.95
PLN 58.85
Free delivery: Aug 13
If paid before 14:00
-5%
Part no. 6977982-3
Mini Cooper R50 R53 R56 R57 R60 Relay No Contact Taubenblau Blue Set 4X 6977982
Promo price
PLN 61.95
PLN 58.85
Free delivery: Aug 13
If paid before 14:00
-5%
Part no. A0035420419
Mercedes W177 W205 W247 Relay Fuse Unit Module 4 Pins Black A0035420419
Promo price
PLN 42.95
PLN 40.80
Delivery: Aug 13
If paid before 14:00
Part no. 431951253H
Audi TT 8N A4 B5 A6 C5 A8 D2 Relay Control Unit Module 12V 4 Pins 431951253H
PLN 42.95
Delivery: Aug 13
If paid before 14:00
-15%
Part no. A0035420219-1
Relay Mercedes W639 W906 5-Pin Black 12V 20A A0035420219 Set X2
Promo price
PLN 94.95
PLN 80.71
Free delivery: Aug 13
If paid before 14:00
-5%
Part no. A0025421119-1
Relay Unit Mercedes W163 W168 W203 W211 4-Pin Black Hella A0025421119 Set 2x
Promo price
PLN 42.95
PLN 40.80
Delivery: Aug 13
If paid before 14:00
Part no. 8D0951253-1
Audi A4 B6 B7 B8 Q7 4L A6 C7 A8 D4 Multi Use Relay Unit Module 4 Pins 8D0951253
PLN 42.95
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 8366282-1
BMW Z1 Z3 E32 E36 E38 E46 X5 E53 Connection Plug Golden Brown Set x2 8366282
Promo price
PLN 94.95
PLN 90.20
Free delivery: Aug 13
If paid before 14:00
-15%
Part no. 5M5T14B192AA-1
Ford Transit Custom Mk8 Relay 4-Pin Black 12V 20A SET X2 5M5T-14B192-AA
Promo price
PLN 85.95
PLN 73.06
Free delivery: Aug 13
If paid before 14:00
Part no. 51888255
Fiat Doblo Mk1 Stilo 192 Diesel Glow Plug Relay Pre-Heating Control ECU 51299012
PLN 89.95
Free delivery: Aug 13
If paid before 14:00
-5%
Part no. 899543000
Porsche Boxster 986 A/C Air Conditioning Relay Control 12V 10A 899543000
Promo price
PLN 42.95
PLN 40.80
Delivery: Aug 13
If paid before 14:00
Part no. 99661510200
Porsche Boxster 986 Rear Spoiler Control Relay 99661510200
PLN 42.95
Delivery: Aug 13
If paid before 14:00
-5%
Part no. 1H5951253
Volkswagen Touareg 7L Relay Alternator Alarm Black 4 Pin 12V No 143 1H5951253
Promo price
PLN 42.95
PLN 40.80
Delivery: Aug 13
If paid before 14:00
Part no. A4709820700
Mercedes W470 Glow Plug Relay Module Unit A4709820700
PLN 94.95
Free delivery: Aug 13
If paid before 14:00
Electrical relays for stable vehicle electrical system performance
Stable and reliable relays for the car's electrical system
Relays are key components of a vehicle's electrical system that enable the control of current flow to various electrical devices, such as lights, fans, fuel pumps, or air conditioning systems. Thanks to relays, it is possible to control high electrical loads using low-voltage signals, which ensures the failure-free operation of vehicle systems. In the Global Parts automotive store, you will find a wide selection of used car parts, including relays, perfectly matched to brands such as BMW, Audi, Mercedes, Volkswagen, Mini, and others.
Construction and operation of an electrical relay in practice
An electrical relay is an electromechanical or solid-state control element that acts as a switch activated by a low-current signal. In a classic 12V automotive solution, it consists of an electromagnetic coil, a core, a movable contact (armature), and a set of power contacts (NO – normally open or NC – normally closed). After applying a control voltage (usually 12V), the coil generates a magnetic field that closes or opens the power circuit. In practice, this means the ability to control devices drawing 20A, 30A, or even 70A using a signal with a load of 0.1–0.2A. This is a huge saving for the control installation and components such as switches, comfort modules, or ECU controllers. In modern vehicles, relays work with BCM modules and CAN systems, ensuring precise adjustment of the operating parameters of the entire installation.
Construction and purpose of automotive electrical relays
Automotive electrical relays are switching elements most often mounted in electrical boxes, the engine compartment, or under the dashboard. A relay is used to separate the control circuit from the power circuit, so that the switch, controller, or body module does not have to carry the full load of the receiver. A typical component has a housing with pin markings, power contacts, a coil, and terminals with a specific layout and number of pins. When selecting, it is worth comparing the OEM number, interchangeable numbers, housing color, and contact configuration.
What functions do relays perform?
Relays play a key role in many of a vehicle's electrical systems:
- Switching high loads – They control high-power electrical devices, minimizing the risk of system overload.
- Protection of electrical systems – They reduce the load in control circuits, protecting against surges and overloads.
- Remote control – They enable the switching of devices on and off using control signals.
- System operation optimization – Thanks to relays, electrical systems operate efficiently and without interference.
Function of relays in starter, lighting, and fan circuits
A relay is used to safely switch on devices that draw more current than the switches in the cabin or controller outputs. In practice, it is responsible for supplying power to the starter, wipers, blower, fuel pump, or radiator fan exactly when a control signal appears. In the case of parts such as a BMW E46 wiper relay, you need to check the pin layout, the marking on the housing, and compatibility with the mounting location in the box. If you are looking for a component such as an Audi A6 C6 starter relay, the current capacity, OEM number, and compatibility with the engine version are key.
Types of relays and their technical parameters
Several basic types of relays are used in automotive installations:
| Relay type | Characteristics | Typical parameters | Application |
|---|---|---|---|
| Electromechanical | Classic design with mechanical contacts and an electromagnetic coil | 12V / 24V, 20–70A | Fuel pump, radiator fan, heating |
| Mini / Micro ISO | Compact housing compliant with the ISO standard | 12V, 20–30A | Low beam, horn, module control |
| Time delay relay | Switching with a (regulated) time delay | 12V, 1–30 s adjustment | Interior lighting, window heating |
| Solid-state relay (SSR) | No mechanical parts, fast switching | 12V, high switching frequency | Electronic systems, ECU controllers |
The most common contact markings are: 30 (power supply), 85 and 86 (coil), 87 (NO contact), 87a (NC contact). Relay matching should take into account voltage compatibility (12V in passenger cars, 24V in trucks), maximum operating current, and contact configuration.
Comparison of relay variants used in cars
| Variant | What to check | Construction and connector | Typical application |
|---|---|---|---|
| Standard 4-pin | OEM number, 30/85/86/87 layout, installation voltage | One pair of power contacts, no 87a contact | Pumps, lights, fans |
| Switching 5-pin | Presence of 87a contact, pin compatibility with the box | Additional NC contact, same housing or similar format | Circuits switching two operating paths |
| Mini or Micro ISO | Housing size, socket type, color and markings | Compact format, depends on the car manufacturer | Modern electrical boxes |
| Time delay or specialized | Delay function, description on housing, control compatibility | Extended electronics inside the housing | Window heating, wipers, comfort modules |
Why is it worth taking care of relays?
A faulty relay can lead to problems with the operation of electrical devices and reduce the reliability of the vehicle's electrical system. Typical symptoms of failure include:
- No response from electrical devices – Lights, fans, or fuel pumps do not work despite functional components.
- Irregular operation – Devices turn on and off randomly.
- No control signal – A damaged relay does not transmit current to the controlled device.
- Relay overheating – May indicate an overload or internal damage. In case of replacement, at Global Parts you will find suitable used parts that will restore the full functionality of the electrical system.
Symptoms and dependencies with other installation elements
In practice, an electrical relay works directly with fuses, control modules, temperature sensors, and the electrical harness. For example, the fuel pump relay in many BMW or Volkswagen models activates only after receiving a signal from the crankshaft position sensor. In the case of a radiator fan, the relay reacts to a signal from the coolant temperature sensor (usually at 92–105°C). Proper parameter matching (e.g., 40A instead of 30A in the fan circuit) ensures operational stability, optimization of current flow, and reduction of voltage drops. This is also important when upgrading LED lighting or installing additional accessories, where load compatibility is of key importance.
Dependencies between relays and cooperating elements
A relay socket is a part of the installation where the control element is seated and from which power is routed to the receiver. The socket works with contacts, pins, wires, and circuit protection, so during diagnosis, you must evaluate not only the relay itself but also the condition of fuses and fuse boxes as well as wires, harnesses, and connectors. When completing a repair for a specific model, e.g., E36 relays, it is good to verify the layout in the box, manufacturer markings, and compatibility with the equipment version. For more complex systems, it is also worth comparing cooperation with electronic control modules and controllers.
How to choose the right relays?
When choosing relays, you should pay attention to several key aspects:
- Vehicle model fitment – Every electrical system has its specific technical requirements. At Global Parts, you will find relays perfectly matched to BMW, Audi, Mercedes, Volkswagen, Mini, and others.
- Electrical parameters – Check the operating voltage, maximum current, and control circuit specification.
- Technical condition – Used relays should be fully functional and free from signs of overheating or mechanical damage.
Criteria for selecting relays according to OEM and mounting parameters
Selecting a relay involves comparing not only voltage and capacity but also the OEM part number, interchangeable numbers, and housing type. Product offers may contain data such as brand, condition, OEM part number, interchangeable numbers, and color, which makes it easier to match to a specific mounting location. For power supply and charging systems, it is worth checking the connection with alternators and generators, especially when the fault manifests as voltage drops or unstable switching of receivers. Complementing the knowledge about cost-effective selection of original parts from dismantling is the article Most popular repairs in Ford cars: why cheap replacements are a false economy and it is better to choose a used original?.
Step-by-step relay matching procedure
- Check the installation voltage (usually 12V).
- Verify the maximum device current (e.g., radiator fan 25–40A).
- Determine the contact configuration (NO/NC).
- Match the housing size (Mini ISO, Micro ISO).
- Compare pin markings (30/85/86/87). This approach allows for maintaining full compatibility with the electrical installation and ensures proper assembly without the need for wiring harness modifications.
Why is it worth choosing used relays?
Used car parts, such as used relays, are an economical solution that allows for savings while maintaining high quality. By choosing used electrical system components, you gain:
- Lower costs – Used relays are significantly cheaper than new ones but offer equally high quality.
- Ecology – Recycling parts supports environmental protection and reduces waste.
- Wide offer – In our store, you will find Automotive electrical relays for the most popular car brands.
How to take care of relays?
To ensure relays work reliably for a long time, it is worth following a few rules:
- Regular inspection – Check the condition of relays during technical inspections.
- Clean connections – Take care of the proper condition of connectors and wires to avoid current flow interference.
- Avoid overloads – Use relays with appropriate parameters for a given electrical system.
- Replace on time – Damaged or worn relays should be replaced to prevent problems with the operation of electrical devices.
FAQ
| Question | Answer |
|---|---|
| What is the construction and purpose of automotive electrical relays? | Automotive electrical relays are elements controlling current flow in the vehicle's installation. A typical relay consists of a housing, a coil, power contacts, and pins with a specific layout, and its location is usually in the fuse box or engine compartment. The task of this component is to separate the control circuit from the circuit powering a device with a higher current draw. |
| What are automotive electrical relays used for? | Relays are used to switch electrical receivers on and off without overloading switches, the ignition switch, or the controller. They enable the operation of systems such as the starter, fuel pump, wipers, radiator fan, or window heating. Without a properly selected relay, the circuit may operate unstably, and connectors and wires are more exposed to overheating. |
| What is the construction and function of a relay socket? | A relay socket is a part of the installation where the relay is seated and to which power and control wires are routed. It consists of a body and contacts corresponding to the pin layout of a given relay. Its function is to ensure a secure electrical connection, proper seating of the component, and easy removal during diagnostics or replacement. |
| How to choose a relay for a specific car? | It is best to compare the OEM number, interchangeable numbers, pin layout, installation voltage, and current capacity. It is also worth checking the car brand, engine version, mounting location, and type of electrical box. If the part has a specific housing color or non-standard marking, these features also help avoid mistakes. |
| What symptoms indicate wear or damage to a relay? | Typical symptoms include no response from the receiver, random switching of the device, excessive heating of the housing, or characteristic clicking without the system working. Sometimes the fault manifests only under load when the contacts are burnt or weakened. In diagnostics, it is also worth checking the fuse, power on the pins, and the condition of the socket. |
| What should be paid attention to when installing a relay? | Before installation, verify the compliance of pin markings and the direction of seating in the socket. It is also important to clean the contacts, check the wires, and ensure that the circuit has no short circuit or excessive current draw. Proper installation should not require harness modifications if the part has been selected according to the OEM number and vehicle version. |
Summary: automotive electrical relays in the Global Parts store
Relays are essential elements of the electrical system that control the operation of many devices in the vehicle. In the Global Parts offer, you will find used components matched to cars of brands such as Mercedes, BMW, Volkswagen, and others, taking into account data important for selection, such as condition, OEM part number, interchangeable numbers, or color. This makes it easier to compare the component with the part dismantled from the car and select the right variant for a specific installation. We invite you to contact us – we are here to help you! For more information and interesting facts, we also invite you to our automotive blog.