BMW Electrical Sensors, Switches, & Relays for BMW 5 Series E34 (1987-1995)

Clear BMW chassis

Please ensure your correct model is selected

Electrical gremlins can be very frustrating. Luckily your BMW's electrical system is better than most, even if it's 25 years old. Here you will find electrical relays, sensors, switches, and modules for the engine, camshaft, and crankshaft. Our parts are OEM, Genuine BMW, or approved aftermarket brands that we have an excellent track record with. There is no middle ground with electrical parts - it either works perfectly or not. And there's nothing more frustrating than a new part that fails right out of the box. So it's important to choose quality replacement parts over a cheap but faulty piece.

Sub-Categories

Sort By:

New Alternator - 140amp | BMW E36 E34 M50 M52 S50 S52
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Bavarian Autosport - Corporate Logo
T#:25042544
Part#: 12311744567
In Stock
Sale - Save 15% $ 219.99

This product was last offered at the strikethrough price on
05-03-2026

$ 186.99 USD
Free Shipping on orders $49 and up
Sale - Save 15%
$ 219.99

This product was last offered at the strikethrough price on
05-03-2026

$ 186.99 USD
Free Shipping on orders $49 and up
Crankshaft Position Sensor - E36 (OBDI), E34 M50/S50
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Bavarian Autosport - Corporate Logo
T#:579816
Part#: 52380
In Stock
Sale - Save 20% $ 48.99

This product was last offered at the strikethrough price on
05-03-2026

$ 39.19 USD
Free Shipping on orders $49 and up
Sale - Save 20%
$ 48.99

This product was last offered at the strikethrough price on
05-03-2026

$ 39.19 USD
Free Shipping on orders $49 and up
Common cause of misfires, poor fuel economy, or a crank no start situation. If your M50 or S50 has any of these symptoms, this crankshaft position sensor from Bavarian Autosport is a likely fix.
ECS Heavy Duty Ground Cable Upgrade (12421737755) - E30, E36, E39, E4...
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
ECS - Corporate Logo
T#:49996974
Part#: 059235LA01
Ships in 4 Business Days
New Item
Sale - Save 23% $ 29.99

This product was last offered at the strikethrough price on
02-04-2026

$ 23.19 USD
Free Shipping
Sale - Save 23%
$ 29.99

This product was last offered at the strikethrough price on
02-04-2026

$ 23.19 USD
Free Shipping

If you're experiencing hard starting, flaky charging, or other electrical issues, your engine ground strap may be the culprit. On older BMWs, the engine ground strap is a thin, non-insulated cable that spans from the engine mount arm to the frame horn. Despite the seemingly simple nature of this part, on older cars, it is known to cause massive headaches. Due to its non-insulated design, years of exposure to water, dirt, and road salt will cause the wire to corrode, ultimately leading to complete failure. A break in this cable will cause an open circuit, resulting in issues with the vehicle's electrical system and potentially leading to a no-start condition.

To solve this issue, ECS has engineered an exact-fit, upgraded ground strap for your BMW! Unlike its OEM counterpart, this design features insulated, large-gauge copper wire for dependable conductivity and long-lasting durability. Additionally, factory-style lugs are zinc-coated, crimped, and soldered, ensuring protection against corrosion and oxidation.

Whether you're replacing a visibly corroded strap or proactively preventing failure, this solution from ECS is sure to provide lasting performance and protection.

FEATURES

Direct-fit replacement and upgrade for E30 (318i/is), E36, E39, E46, and others Solves intermittent grounding issues caused by aging OEM straps Clean, stealthy design that fits seamlessly in factory engine bays Factory length and lug orientation for drop-in fitment 2 AWG tinned copper cable for excellent conductivity and corrosion resistance Zinc-coated lugs, crimped and soldered to resist moisture and oxidation Black UL1015-grade insulation withstands oil, heat, and abrasion Discreet ECS label for a clean, OEM+ look Replaces OEM part numbers 12421737755 and 12421714262.

Show More Show Less

Braille Performance Lightweight AGM Battery - B14115 - 11.5lbs ...
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Braille - Corporate Logo
T#:558037
Part#: B14115
Ships in 5 Business Days
$ 204.99 USD
Free Shipping on orders $49 and up
When building a car for the track, one of the most important factors to consider is weight. Stock batteries can weigh up to almost 50 pounds and are unnecessarily large, designed to power a host of systems not normally used in a track car (radios, lighting, etc.). What can you do to cut weight the weight without affecting your cars operation? This is where Braille Battery comes in with their long line of performance lightweight battery options! Designed to provide the highest cranking power possible while being up to 75% lighter, Braille Battery is one of the foremost leaders in automotive racing batteries with nothing but high quality, high output batteries in mind!
Show More Show Less

Braille Performance Lightweight Advanced AGM Battery - B2015 - 15lbs ...
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Braille - Corporate Logo
T#:558038
Part#: B2015
Ships in 8 Business Days
$ 237.99 USD
Free Shipping on orders $49 and up
When building a car for the track, one of the most important factors to consider is weight. Stock batteries can weigh up to almost 50 pounds and are unnecessarily large, designed to power a host of systems not normally used in a track car (radios, lighting, etc.). What can you do to cut weight the weight without affecting your cars operation? This is where Braille Battery comes in with their long line of performance lightweight battery options! Designed to provide the highest cranking power possible while being up to 75% lighter, Braille Battery is one of the foremost leaders in automotive racing batteries with nothing but high quality, high output batteries in mind! The B2015 is Braille's most popular non-carbon racing battery and is able to start larger engines easily for racing and offers daily driving capability for most 4 and 6 cylinders engine vehicles. Physical Specifications: BCI Group: All sizes Weight: 15lbs / 6.8kg Length: 6.8" / 173mm Width: 3.4" / 86mm Height: 6.1" / 155mm Polarity: Right Side Positive Performance Specifications: Voltage: 12 Full Charge Voltage: 13.2 Pulse Cranking Amps (PCA): 1067 Amp Hour (AH): 21 Life Cycle @ 10% DOD: 3100 *THIS BATTERY REQUIRES A CUSTOM MOUNTING SOLUTION. The size and weight are significantly smaller than a stock battery and will not be held in place by the stock battery mount*
Show More Show Less
Braille Lightweight Advanced AGM Battery - B3121 - 21lbs
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Braille - Corporate Logo
T#:558042
Part#: B3121
Ships in 5 Business Days
$ 270.99 USD
Free Shipping on orders $49 and up
When building a car for the track, one of the most important factors to consider is weight. Stock batteries can weigh up to almost 50 pounds and are unnecessarily large, designed to power a host of systems not normally used in a track car (radios, lighting, etc.). What can you do to cut weight the weight without affecting your car's operation? This is where Braille Battery comes in with their long line of performance lightweight battery options! Designed to provide the highest cranking power possible while being up to 75% lighter, Braille Battery is one of the foremost leaders in automotive racing batteries with nothing but high quality, high output batteries in mind! The B3121 battery from Braille is their lightest do-everything battery available, offering 1380 pulse cranking amps that can crank over V8 engines with ease while still coming in at under 22 pounds, half of the weight of a standard Group 34 battery! This is thanks to their Advanced AGM racing technology that allows them to put a ton of power into a very small package. Physical Specifications: BCI Group: All sizes Weight: 21lbs / 9.5kg Length: 6.6" / 168mm Width: 5.2" / 132mm Height: 6.8" / 173mm Polarity: Right Side Positive Terminal Type: Steel terminal block with M6 bolt Performance Specifications: Voltage: 12v Recharge Voltage: 14.4V – 14.6V Maintenance charge voltage: 13.8V 5s Pulse Cranking Amps (PCA): 1380 10s PDC: 124 Amp Hour (Ah): 31 Watt Hour (Wh): 372 Life Cycle @ 10% DOD: 3100 Charging Temperature 0C to 50C Discharge Temperature range -40C to +60C Storage temperature -40C to +60C *THIS BATTERY REQUIRES A CUSTOM MOUNTING SOLUTION. The size and weight are significantly smaller than a stock battery and will not be held in place by the stock battery mount*
Show More Show Less

Innovate LC-2 Wideband O2 Controller Kit
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Innovate Motorsports - Corporate Logo
T#:28836410
Part#: 38770
In Stock
$ 212.99 USD
Free Shipping on orders $49 and up

Features & Benefits:

Two configurable linear 0-5V analog outputs Ability to calibrate O2 sensors for maximum accuracy Includes LC-2 controller and Bosch wideband O2 sensor Comes with a program cable, manual, and a 10 ft. sensor cable Includes a 1-inch mild steel exhaust bung Innovate MTS serial in/out capability Integrated dual-color status LED (green/red) Patented DirectDigital™ wideband sensor control Positive lock connectors for all connections Real-time display data on screen or with the powerful LogWorks software Range:

AFR (Air-Fuel Ratio) range from 7.4:1 to 22.4:1 (0.5 to 1.5 lambda)

Show More Show Less
Superior Bass Sports Horn Kit 330Hz + 400Hz 112Db
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
PIAA - Corporate Logo
T#:31158805
Part#: 85115
Ships on Jul 30, 2026
$ 77.99 USD
Free Shipping on orders $49 and up
Superior Bass Sports Horn Kit 330Hz + 400Hz 112Db

The Superior Bass Sports Horn Kit 330Hz + 400Hz 112Db is designed to make sure your presence is known with powerful, attention-grabbing sound. These high-performance sports horns feature:

  • Impressive Loudness: Delivers a powerful 112 decibels, ensuring you’re heard in any situation.
  • Dual Frequency: Includes 330Hz and 400Hz horns for a dynamic and distinct sound.
  • Lightweight & Durable: Constructed for easy installation with weather-resistant covers, built to withstand the elements.
  • Easy Installation: Quick and straightforward to install, enhancing vehicle safety with minimal effort.

The kit is a must-have for anyone looking to enhance their vehicle’s horn performance and visibility on the road.

Show More Show Less

Braille Performance GreenLite Lithium-ION Battery - G30 - 5.5lbs ...
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Braille - Corporate Logo
T#:558046
Part#: G30
Ships in 7 Business Days
$ 522.99 USD
Free Shipping on orders $49 and up
The G30 lithium battery from Braille is designed for the Import Tuner market (4 and 6 cylinder) for track use and has enough power for small black V8 race cars and hot rods with light electrical demands/accessories and standard compression. The G30 comes in the popular ETX 30 Group size, just like the B3121 AGM, so it is small and light enough to mount in a variety of locations. Incorporated in this battery is the same technology used in their race winning batteries used by nearly every OEM developer in classes ranging from SCCA to Formula 1.
Show More Show Less

Bass Tone Sports Horn Kit 400Hz + 500Hz, 115Db
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
PIAA - Corporate Logo
T#:31589317
Part#: 85110
Ships in 9 Business Days
$ 77.99 USD
Free Shipping on orders $49 and up
OMP Battery Cut Off Switch / Kill Switch
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
OMP - Corporate Logo
T#:1614
Part#: EA-462
Back Ordered
$ 65.00 USD
Free Shipping
$ 65.00 USD
Free Shipping
OMP Battery Cut Off Switch / Kill Switch, for use in racecars as an emergency "kill switch", to depower the electrical system in the event of a crash or other emergency. This cut off switch is FIA approved, has 6 poles and alternator protection, as well as a removable key.
Show More Show Less
Precision Raceworks Ethanol Sensor Breakout Harness
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Precision Raceworks - Corporate Logo
T#:35559424
Part#: 201-0411
In Stock
$ 35.99

This product was last offered at the strikethrough price on
01-22-2026

$ 34.99 USD
Free Shipping on orders $49 and up
$ 34.99 USD
Free Shipping on orders $49 and up
n Ethanol Sensor Breakout Harness provides a clean wiring solution by splitting the signal from your ethanol content sensor between two analyzers, such as an ECU/controller and a gauge or Bluetooth display, without modifying your existing harness.his setup enables real-time ethanol level monitoring and facilitates comprehensive DME/ECU adjustments for enhanced automotive performance.citeturn0search0
Show More Show Less


AAF Oil Pressure Sensor Relocate Kit - M20
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Advanced Auto Fabrication - Corporate Logo
T#:7593105
Part#: 116177
Ships in 3 Business Days
$ 69.99 USD
Free Shipping on orders $49 and up
Since 2010, Advanced Auto Fabrication has been producing and developing both parts and full fledged race cars. Their knowledge base covers a wide range of vehicles both domestic and imported. In the specific case of BMW, the team at AAF has a particular affinity for building and designing components for BMW race cars. AAF's Oil Pressure Sensor Relocation Kit allows for an aftermarket low pressure switch as well as oil pressure sensor, or two 1/8' NPT pressure sensors to be installed. This can allow a gauge or light to be on the dash and still log oil pressure in a data logger. This kit also moves the oil pressure sensor away from the engine and onto the chassis (or any other spot) where is it much easier to access, or install larger size diameter sensors. Fits all M20 Engines. Features: 4AN Stainless Steel Braided Line Banjo Bolt and Fitting (installs onto block) 3 Way 1/8' NPT Tee Fitting, for hose from block and 2 sensors. Note: This kit does not come with sensors – the factory low pressure switch can NOT be used. An aftermarket 1/8″ NPT low pressure switch can be used with the factory wire.
Show More Show Less
LK-2M 2 Pin Connector Package
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
ECS - Corporate Logo
T#:40072446
Part#: LK2M
In Stock
Sale - Save 20% $ 5.99

This product was last offered at the strikethrough price on
05-03-2026

$ 4.79 USD
Free Shipping on orders $49 and up
Sale - Save 20%
$ 5.99

This product was last offered at the strikethrough price on
05-03-2026

$ 4.79 USD
Free Shipping on orders $49 and up

Includes connector housing with terminals and seals. Commonly used for the engine oil pressure switch.

ECS Tuning replacement harness connectors include all necessary pins and wire seals for a complete harness repair. Whether you have a broken harness connector or need a complete wiring repair, we have the components you need.

Each connector includes an additional terminal in case one becomes lost or damaged during installation.

Suggested tools:

Suggested crimping pliers: T#387193
Wire De-pin tools:
12pc De-Pin Tool Set - T#386379
23pc De-Pin Tool Set - T#641943

Show More Show Less
3 Pin Connector
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
ECS - Corporate Logo
T#:33412930
Part#: 12521706096
In Stock
Sale - Save 11% $ 10.99

This product was last offered at the strikethrough price on
05-03-2026

$ 9.78 USD
Free Shipping on orders $49 and up
Sale - Save 11%
$ 10.99

This product was last offered at the strikethrough price on
05-03-2026

$ 9.78 USD
Free Shipping on orders $49 and up

Includes connector housing with terminals and seals. Commonly used for the idle air control valve (IACV).

ECS Tuning replacement harness connectors include all necessary pins and wire seals for a complete harness repair. Whether you have a broken harness connector or need a complete wiring repair, we have the components you need.

Each connector includes an additional terminal in case one becomes lost or damaged during installation.

*OEM cross reference PN# 12521706096 - Commonly used for the idle air control valve (IACV).

Please reference the original part number from the existing connector to confirm fitment, before ordering.

Suggested tools:

Suggested crimping pliers: T#387193
Wire De-pin tools:
12pc De-Pin Tool Set - T#386379
23pc De-Pin Tool Set - T#641943

Show More Show Less

Wire With Terminals For 90 Degree 6 Pin Bulkhead (Red)
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Precision Raceworks - Corporate Logo
T#:38161695
Part#: 201-0360-RED
Ships in 6 Business Days
$ 5.99 USD
Free Shipping on orders $49 and up
Upgrade any wiring system with this optimal solution, ensuring reliability and durability in any demanding automotive application. Red in color and 12 Gauge.

Wire With Terminals For 90 Degree 6 Pin Bulkhead - Black - Dual 18 Ga...
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Precision Raceworks - Corporate Logo
T#:38161710
Part#: 201-0362
Ships in 9 Business Days
$ 4.99 USD
Free Shipping on orders $49 and up
Upgrade any wiring system with this optimal solution, ensuring reliability and durability in any demanding automotive application. Black in color and 18 Gauge dual wire.
Wire With Terminals For 90 Degree 6 Pin Bulkhead - Blue
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Precision Raceworks - Corporate Logo
T#:38161703
Part#: 201-0360-BLU
Ships in 9 Business Days
$ 4.99 USD
Free Shipping on orders $49 and up
Upgrade any wiring system with this optimal solution, ensuring reliability and durability in any demanding automotive application. Blue in color and 12 Gauge.

Wire With Terminals For 90 Degree 6 Pin Bulkhead - Yellow
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Precision Raceworks - Corporate Logo
T#:38161692
Part#: 201-0360-YEL
Ships in 9 Business Days
$ 4.99 USD
Free Shipping on orders $49 and up
Upgrade any wiring system with this optimal solution, ensuring reliability and durability in any demanding automotive application. Yellow in color and 12 Gauge.
Wire With Terminals For 90 Degree 6 Pin Bulkhead (Black) 12 Gauge ...
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Precision Raceworks - Corporate Logo
T#:38161711
Part#: 201-0360-BLK
Ships in 9 Business Days
$ 4.99 USD
Free Shipping on orders $49 and up
Upgrade any wiring system with this optimal solution, ensuring reliability and durability in any demanding automotive application. Black in color and 12 Gauge.

Wire With Terminals For 90 Degree 6 Pin Bulkhead (White)
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Precision Raceworks - Corporate Logo
T#:38161693
Part#: 201-0360-WHT
Ships in 9 Business Days
$ 4.99 USD
Free Shipping on orders $49 and up
Upgrade any wiring system with this optimal solution, ensuring reliability and durability in any demanding automotive application. White in color and 12 Gauge.

Wire With Terminals For 90 Degree 6 Pin Bulkhead - Orange
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Precision Raceworks - Corporate Logo
T#:38161698
Part#: 201-0360-ORG
Ships in 9 Business Days
$ 4.99 USD
Free Shipping on orders $49 and up
Upgrade any wiring system with this optimal solution, ensuring reliability and durability in any demanding automotive application. Orange in color and 12 Gauge.
Wire With Terminals For 90 Degree 6 Pin Bulkhead (Green)
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
Precision Raceworks - Corporate Logo
T#:38161687
Part#: 201-0361-GRN
Ships in 9 Business Days
$ 3.99 USD
Free Shipping on orders $49 and up
Upgrade any wiring system with this optimal solution, ensuring reliability and durability in any demanding automotive application. Green in color and 18 Gauge.
2 Pin Connector
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
ECS - Corporate Logo
T#:33412928
Part#: 12521427615
Ships on Jul 27, 2026
Sale - Save 37% $ 7.99

This product was last offered at the strikethrough price on
05-03-2026

$ 5.01 USD
Free Shipping on orders $49 and up
Sale - Save 37%
$ 7.99

This product was last offered at the strikethrough price on
05-03-2026

$ 5.01 USD
Free Shipping on orders $49 and up
Includes connector housing with terminals and seals. Commonly used for the engine oil pressure switch. ECS Tuning replacement harness connectors include all necessary pins and wire seals for a complete harness repair. Whether you have a broken harness connector or need a complete wiring repair, we have the components you need. Each connector includes an additional terminal in case one becomes lost or damaged during installation. *OEM cross reference PN# 12521427615 - Commonly used for the engine oil pressure switch. Please reference the original part number from the existing connector to confirm fitment, before ordering. Suggested tools: Suggested crimping pliers: T#387193 Wire De-pin tools: 12pc De-Pin Tool Set - T#386379 23pc De-Pin Tool Set - T#641943
Show More Show Less


2 Pin Connector
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms
ECS - Corporate Logo
T#:33412932
Part#: 61132359999
Ships on Jul 28, 2026
Sale - Save 25% $ 10.99

This product was last offered at the strikethrough price on
05-03-2026

$ 8.24 USD
Free Shipping on orders $49 and up
Sale - Save 25%
$ 10.99

This product was last offered at the strikethrough price on
05-03-2026

$ 8.24 USD
Free Shipping on orders $49 and up

Includes connector housing with terminals and seals. Commonly used for the coolant level sensor.

ECS Tuning replacement harness connectors include all necessary pins and wire seals for a complete harness repair. Whether you have a broken harness connector or need a complete wiring repair, we have the components you need.

Each connector includes an additional terminal in case one becomes lost or damaged during installation.

*OEM cross reference PN# 61132359999 - Commonly used for the coolant level sensor.

Please reference the original part number from the existing connector to confirm fitment, before ordering.

Suggested tools:

Suggested crimping pliers: T#387193
Wire De-pin tools:
12pc De-Pin Tool Set - T#386379
23pc De-Pin Tool Set - T#641943

Show More Show Less