BMW Electrical Sensors, Switches, & Relays for BMW 8 Series E31 (1991-1997)

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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.

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ECS - Corporate Logo
T#:49996974
Part#: 059235LA01
In Stock
New Item
Sale - Save 20% $ 29.99

This product was last offered at the strikethrough price on
06-14-2026

$ 23.99 USD
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Sale - Save 20%
$ 29.99

This product was last offered at the strikethrough price on
06-14-2026

$ 23.99 USD
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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.

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Innovate Motorsports - Corporate Logo
T#:28836410
Part#: 38770
In Stock at Vendor
$ 212.99 USD
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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)

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Braille - Corporate Logo
T#:558042
Part#: B3121
Ships in 6 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*
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Bosch Air Temperature Sensor - E31, E32, E34, E36, E38
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!
Bosch - Corporate Logo
T#:555413
Part#: 13621725323
In Stock
$ 44.99

This product was last offered at the strikethrough price on
03-09-2026

$ 34.33 USD
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$ 34.33 USD
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Located on the intake manifold or intake box

Permatex - Corporate Logo
T#:3672391
Part#: 22058
In Stock at Vendor
$ 20.99 USD
Free Shipping on orders $49 and up
Protects electrical connections and wiring from salt, dirt and corrosion
OEM Bosch BMW Knock Sensor - M62 E39 E38 E31
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!
Bosch - Corporate Logo
T#:397564
Part#: 12141741648
In Stock
$ 64.99 USD
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$ 64.99 USD
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Knock sensors detect pings in the engine and adjust ignition timing to restore perfect operation. Faulty knock sensors will throw engine codes or even lead to engine damage. Replace your sensor with a reliable, high quality Bosch sensor to ensure proper engine ignition timing.

Bosch # 12141741648 OEM replacement for BMW part # 12141741648.

Bosch is one of the largest OEM producers of Genuine BMW and aftermarket parts in the world, providing parts for almost every major automotive manufacturer. Bosch has likely s  eupplied many of the original electrical (and mechanical) parts for your BMW. Thanks to their quality, high durability, and reliability, you should expect a long service life from Bosch products.

As a leading source of high performance BMW parts and accessories since 1993, we at Turner Motorsport are honored to be the go-to supplier for tens of thousands of enthusiasts the world over. With over two decades of parts, service, and racing experience under our belt, we provide only quality performance and replacement parts.  All of our performance parts are those we would (and do!) install and run on our own cars, as well as replacement parts that are Genuine BMW or from OEM manufacturers. We only offer parts we know you can trust to perform!

Fits the following vehicles:
1996-09/1999 E39 BMW 540i
1995-09/1999 E38 BMW 740i 740iL
1990-1999 E31 BMW 840Ci

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Bosch Knock Sensor - E31, E32, E34, E38
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!
Bosch - Corporate Logo
T#:579188
Part#: 261231074
In Stock at Vendor
$ 111.99

This product was last offered at the strikethrough price on
05-07-2026

$ 108.00 USD
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$ 108.00 USD
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Controls the timing and air/fuel mixture of your engine
Bosch Alternator - 1993-1995 V8 - E34 530i/540i & E32 740i/740il ...
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!
Bosch - Corporate Logo
T#:1976
Part#: AL0742X
In Stock at Vendor
$ 475.99

This product was last offered at the strikethrough price on
05-07-2026

$ 464.99 USD
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$ 464.99 USD
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Replacement Bosch alternator for the 1993-1995 V8 engine (M60), found in the E34 530i & 540i, and E32 740i/740iL (thru 1994). Bosch is an original equipment supplier to BMW, and is the finest and most recognized German brand of alternator available. Buy only the best alternator for your BMW -- buy a Bosch alternator.

Bosch is one of the largest OEM producers of Genuine BMW and aftermarket parts in the world, providing parts for almost every major automotive manufacturer. Bosch has likely supplied many of the original electrical (and mechanical) parts for your BMW. Thanks to their exacting assembly process and high level of durability you can expect a long service life from all Bosch products.

A refundable core charge must be applied to this alternator. Upon receipt of your rebuildable alternator core, you will be refunded the core charge.

This Bosch Alternator fits the following BMWs:
1994-1995 E34 5 Series V8 530i & 540i
1992-1995 E32 7 Series V8 740i & 740iL
1994-1995 E31 8 Series V8 840C/ 840i

Includes $65.00 core charge to be refunded on return of your rebuildable core.

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OMP - Corporate Logo
T#:1614
Part#: EA-462
In Stock
$ 65.00 USD
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$ 65.00 USD
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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.
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Bosch Alternator - 120 Amp - E31 E38 E39
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!
Bosch - Corporate Logo
T#:186964
Part#: AL0733X
In Stock
$ 496.99

This product was last offered at the strikethrough price on
02-14-2026

$ 319.99 USD
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$ 319.99 USD
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120 amp Bosch alternator for many BMW M62 V8's with 7 Poly Groove Pulley. Bosch is an original equipment supplier to BMW, and is the finest and most recognized German brand of alternator available. Buy only the best alternator for your BMW -- buy a Bosch alternator. Can be used in place of bmw part number. 12311433266

Bosch is one of the largest OEM producers of Genuine BMW and aftermarket parts in the world, providing parts for almost every major automotive manufacturer. Bosch has likely supplied many of the original electrical (and mechanical) parts for your BMW. Thanks to their exacting assembly process and high level of durability you can expect a long service life from all Bosch products.

A refundable core charge must be applied to this alternator. Upon receipt of your rebuildable alternator core, you will be refunded the core charge.

This Bosch Alternator fits the following BMWs:
1997-1998 E39 5 Series 540i
1997-1998 E38 BMW 740i 740il
1996-1999 E31 BMW 840i 840ci

Includes $65.00 core charge to be refunded on return of your rebuildable core.

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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
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Braille - Corporate Logo
T#:558046
Part#: G30
Ships on Aug 6, 2026
$ 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.
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Bosch Starter Motor - E32 750il E38 750il E31 850i 850ci
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!
Bosch - Corporate Logo
T#:1175
Part#: SR444X
In Stock at Vendor
Sale - Save 5% $ 279.99

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

$ 265.75 USD
Sale - Save 5%
$ 279.99

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

$ 265.75 USD

Bosch is one of the largest OEM producers of Genuine BMW and aftermarket parts in the world, providing parts for almost every major automotive manufacturer. Bosch has likely supplied many of the original electrical (and mechanical) parts for your BMW. Thanks to their exacting assembly process and high level of durability you can expect a long service life from all Bosch products.

This genuine Bosch Starter fits the following BMWs:
1988-1991 E32 7 Series 750il
1995-2001 E38 7 Series 750il
1991-1998 E31 8 Series 850i 850ci

 

Includes $75.00 core charge to be refunded on return of your rebuildable core.

 

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ATE - Corporate Logo
T#:1195880
Part#: 34331150922
Ships in 4 Business Days
$ 147.43 USD
Free Shipping on orders $49 and up
$ 147.43 USD
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Leaking or malfunctioning oil pressure switches can be disastrous
Bosch Starter Motor - E39 E38 E32 E34 X5 E53
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!
Bosch - Corporate Logo
T#:2024
Part#: SR0446X
Ships on Aug 14, 2026
$ 477.99 USD
Free Shipping
$ 477.99 USD
Free Shipping

Bosch is one of the largest OEM producers of Genuine BMW and aftermarket parts in the world, providing parts for almost every major automotive manufacturer. Bosch has likely supplied many of the original electrical (and mechanical) parts for your BMW. Thanks to their exacting assembly process and high level of durability you can expect a long service life from all Bosch products.

This genuine Bosch Starter motor fits the following BMWs:
1992-1994 E32 7 Series 740i, 740il
1993-1995 E34 5 Series 530i, 530i wagon, 540i
1995-2001 E38 7 Series 740i, 740il
1997-2003 E39 5 Series 540i M5
2000-2003 E53 X5 X5 4.4i X5 4.6is - M62 engine
2000-2003 Z8 Z8

 

Includes $100.00 core charge to be refunded on return of your rebuildable core.

 

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OEM Bosch Fuel Pump Relay -- e30 e36 e46 e28 e34 e39 e24 e23 e32 e38 ...
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!
Bosch - Corporate Logo
T#:2857
Part#: 61311373585
In Stock
$ 11.99 USD
Free Shipping on orders $49 and up

If you have a faulty fuel pump relay, fuel will not be pumped to the engine and your engine may not start. Replace your relay with this high quality Bosch replacement to restore fuel pump operation.

Bosch is one of the largest OEM producers of Genuine BMW and aftermarket parts in the world, providing parts for almost every major automotive manufacturer. Bosch has likely supplied many of the original electrical (and mechanical) parts for your BMW. Thanks to their quality, high durability, and reliability, you should expect a long service life from Bosch products.

As a leading source of high performance BMW parts and accessories since 1993, we at Turner Motorsport are honored to be the go-to supplier for tens of thousands of enthusiasts the world over. With over two decades of parts, service, and racing experience under our belt, we provide only quality performance and replacement parts.  All of our performance parts are those we would (and do!) install and run on our own cars, as well as replacement parts that are Genuine BMW or from OEM manufacturers. We only offer parts we know you can trust to perform!

This 4 prong relay fits many BMW's and fulfulls a variety of functions. Please check your relay pins configuration to ensure the proper fitment. Fits BMW 2002, e30 e36 e46 e28 e34 e39 e24 e23 e32 e38 e31 z3


This item fits the following BMWs:
1970-1976 2002 BMW 1600 2002 2002tii
1984-1991 E30 BMW 318i 318is 318ic 325e 325es 325i 325ic 325is 325ix M3
1992-1998 E36 BMW 318i 318is 318ti 318ic 323is 323ic 325i 325is 325ic 328i 328is 328ic M3
1999-2005 E46 BMW 323i 323ci 325i 325ci 325xi 328i 328ci 330i 330ci 330xi M3
1982-1988 E28 BMW 524td 528e 533i 535i 535is M5
1989-1995 E34 BMW 525i 530i 535i 540i M5
1997-2003 E39 BMW 525i 528i 530i 540i M5
1982-1989 E24 BMW 633csi 635csi M6
1981-1987 E23 BMW 733i 735i
1988-1994 E32 BMW 735i 735il 740i 740il 750il
1995-2001 E38 BMW 740i 740il 750il
1990-1999 E31 BMW 840i 840ci 850i 850ci 850csi
1997-2002 Z3 BMW Z3 1.9 Z3 2.3 Z3 2.5i Z3 2.8 Z3 3.0i M coupe M Roadster

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ECS - Corporate Logo
T#:40072446
Part#: LK2M
In Stock
Sale - Save 29% $ 6.99

This product was last offered at the strikethrough price on
06-14-2026

$ 4.94 USD
Free Shipping on orders $49 and up
Sale - Save 29%
$ 6.99

This product was last offered at the strikethrough price on
06-14-2026

$ 4.94 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

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Performance Tool - Corporate Logo
T#:1809154
Part#: W5368
Ships in 1 Business Day
$ 13.68 USD
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A must for any toolbox.

15A Fuse - Priced Each
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!
Bosch - Corporate Logo
T#:375327
Part#: 61131372626
In Stock at Vendor
$ 2.03 USD
Free Shipping on orders $49 and up
Bosch Knock Sensor - E31, E32, E34, E38
2X Entries For Our G87 M2 Sweepstakes! We Price Match - Give Us A Call or Chat!
Bosch - Corporate Logo
T#:13073
Part#: 12141702163
In Stock at Vendor
$ 78.99

This product was last offered at the strikethrough price on
05-07-2026

$ 76.99 USD
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$ 76.99 USD
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Bosch BMW PING SENSOR:121060

Precision Raceworks - Corporate Logo
T#:38161695
Part#: 201-0360-RED
Ships in 6 Business Days
$ 5.99 USD
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Upgrade any wiring system with this optimal solution, ensuring reliability and durability in any demanding automotive application. Red in color and 12 Gauge.

Precision Raceworks - Corporate Logo
T#:38161710
Part#: 201-0362
Ships in 9 Business Days
$ 4.99 USD
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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.
Precision Raceworks - Corporate Logo
T#:38161698
Part#: 201-0360-ORG
Ships in 9 Business Days
$ 4.99 USD
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Upgrade any wiring system with this optimal solution, ensuring reliability and durability in any demanding automotive application. Orange in color and 12 Gauge.
Precision Raceworks - Corporate Logo
T#:38161711
Part#: 201-0360-BLK
Ships in 9 Business Days
$ 4.99 USD
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Upgrade any wiring system with this optimal solution, ensuring reliability and durability in any demanding automotive application. Black in color and 12 Gauge.


Precision Raceworks - Corporate Logo
T#:38161692
Part#: 201-0360-YEL
Ships in 9 Business Days
$ 4.99 USD
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Upgrade any wiring system with this optimal solution, ensuring reliability and durability in any demanding automotive application. Yellow in color and 12 Gauge.
Precision Raceworks - Corporate Logo
T#:38161687
Part#: 201-0361-GRN
Ships in 9 Business Days
$ 3.99 USD
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Upgrade any wiring system with this optimal solution, ensuring reliability and durability in any demanding automotive application. Green in color and 18 Gauge.
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.

Precision Raceworks - Corporate Logo
T#:38161703
Part#: 201-0360-BLU
Ships in 9 Business Days
$ 4.99 USD
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Upgrade any wiring system with this optimal solution, ensuring reliability and durability in any demanding automotive application. Blue in color and 12 Gauge.

ECS - Corporate Logo
T#:33412928
Part#: 12521427615
Ships in 3 Business Days
Sale - Save 25% $ 7.99

This product was last offered at the strikethrough price on
06-14-2026

$ 5.99 USD
Free Shipping on orders $49 and up
Sale - Save 25%
$ 7.99

This product was last offered at the strikethrough price on
06-14-2026

$ 5.99 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
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ECS - Corporate Logo
T#:33412932
Part#: 61132359999
Ships in 4 Business Days
Sale - Save 25% $ 10.99

This product was last offered at the strikethrough price on
06-14-2026

$ 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
06-14-2026

$ 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

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