BMW Electrical Sensors, Switches, & Relays for BMW Z3 (1996-2002)

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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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Turner Alpha-N IAT Sensor Relocation Kit - S54 S62 S85
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Drilling Required!
Turner Motorsport - Corporate Logo
T#:597496
Part#: 014579TMSKT
In Stock
Sale - Save 25% $ 136.36

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06-14-2026

$ 102.27 USD
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Sale - Save 25%
$ 136.36

This product was last offered at the strikethrough price on
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$ 102.27 USD
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Turner Plug-and-Play IAT Relocation Kit
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Turner Motorsport - Corporate Logo
T#:391751
Part#: 014579TMS
Ships in 2 Business Days
Sale - Save 16% $ 213.99

This product was last offered at the strikethrough price on
06-13-2026

Starting at $ 179.23 USD
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Sale - Save 16%
$ 213.99

This product was last offered at the strikethrough price on
06-13-2026

Starting at $ 179.23 USD
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All vehicles will lose some degree of performance due to heat soak under the right operating conditions.  Engine management systems constantly monitor operating conditions and modifying parameters based on sensor inputs. BMW integrated the intake air temp sensor in the MAF housing on models such as the E39 M5, and, being sandwiched behind a hot radiator and in some applications next to an even hotter valve cover, this is less than ideal for performance applications. Absorbing excess heat from its surroundings, the MAF can’t shed it fast enough, and the ECU reads an inaccurately high intake air temperature. Compensating for this false hot air measurement, the ECU pulls timing and runs a richer fuel mixture, resulting in a significant loss of torque.

What can you do?  Locate an intake air temp sensor in a location where it can properly measure incoming air temps and where it's less prone to heat soak. Mounting the sensor further away from the heat source and isolating it from the MAF housing, it can both resist the effects of heat soak longer and respond to temperature changes more quickly.  The result is you’ll experience reduced torque loss and more consistent power output when you’re pushing your engine hard. 

The Turner engineering team was initially skeptical of the claimed performance benefits of this modification. They first set out validate the functionality and performance benefit of a temp sensor relocation. Replicating stop-and-go traffic heat soak in a 2001 540i was a simple task in a controlled environment - their dynometer. First the car was heat soaked to simulate being stuck in traffic or moving at low speeds by running the car four times on the dyno with the dyno's cooling fans disabled. The fans were then turned on for three more runs to observe the recovery rate once air flow was reintroduced. The test: following this procedure once with a stock IAT, and once with their relocation kit in place. 

The result? Turner recovered 11lb-ft torque at 2500rpm through use of their relocation kit, with even greater recovery to be found for M5 owners. Here are the heat soak-related torque losses Turner experienced:

Stock IAT location:
18rwtq at 2500rpm
10rwtq at 3000rpm
9rwtq at 3700rpm

Turner IAT Relocation:
7rwtq at 2500rpm
5rwtq at 3000rpm
5rwtq at 3700rpm

**Click here for installation instructions**

The Turner engineering team designed a complete plug and play kit (unlike all other options on the market) that makes for quick, easy, and reversible installation. Weather-sealed connectors keep out the elements, while sheathed wiring offers a clean appearance underhood. With a harness nearly 3 feet long - the Turner IAT relocation kit offers flexibility in positioning, but not too long that you're left with unsightly excess wiring. Turner recommends positioning the sensor in a location away from engine heat, but still within the intake ducting to achieve accurate intake temp readings - such as the far side of the base of the airbox. Vehicles with cold air intakes with cone-style filters can even position the sensor in the end of the filter. Simply drill a hole in your (cool) location of choice and plug in the harness. More information including installation instructions and some good examples of sensor mounting locations can be found in our DIY PDF. 

We include everything you need to relocate your IAT, just select your desired sensor brand below - Genuine BMW or original equipment Beru.

Also the perfect plug-n-play option for anyone looking to upgrade their intake to utilize an Alpha-N tune!

Note for vehicles with M62 engine: applicable to 1999 and up

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Turner Plug-And-Play Alpha-N IAT Sensor Relocation Kit
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Turner Motorsport - Corporate Logo
T#:638071
Part#: 014579TMSKT1
In Stock
Sale - Save 25% $ 150.99

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

$ 113.24 USD
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Sale - Save 25%
$ 150.99

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

$ 113.24 USD
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What can you do to get rid of this heat soak? Turner designed an IAT relocation kit that moves the intake air temp sensor to a cooler location. Mounting the sensor further away from the heat source and isolating it from the MAF housing, it can both resist the effects of heat soak longer and respond to temperature changes more quickly. The result is you’ll experience reduced torque loss and more consistent power output when you’re pushing your engine hard.
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OEM VDO Camshaft Reference Sensor -- M52/S52
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Continental - Corporate Logo
T#:1110
Part#: 12141703221
In Stock
$ 67.99 USD
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$ 67.99 USD
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This is a common failure item which can cause a check engine light, and rough engine running on the M52/S52 engines (328, M3, 528 thru 98, Z3 2.8, & M Roadster/Coupe thru 2000). If you have received an engine fault code suggesting "cam shaft reference sensor" or similar, this is most likely the cuprit. Once replaced, you will need to clear the fault code. We recommend replacing the cam position sensor o-ring at the same time.

OEM VDO is one of the largest OE providers in the world, supplying numerous vehicle brands, including BMW, with many of their genuine parts that build the vehicle before they ever reach the car lot. Entrusted by many of the top names in automotives and with their proven history of reliability, it makes all of us here at Turner confident that their line of OEM replacement parts are a perfect option to restore your vehicles original operation and performance. The same great quality or higher than Genuine BMW parts at a lower cost.

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

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ECS Heavy Duty Ground Cable Upgrade (12421737755) - E30, E36, E39, E4...
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ECS - Corporate Logo
T#:49996974
Part#: 059235LA01
In Stock
New Item
Sale - Save 20% $ 29.99

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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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OEM Starter Motor - E46 M3 2001-2006
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Valeo - Corporate Logo
T#:2988
Part#: 12417835735
In Stock
$ 400.99

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

$ 293.99 USD
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$ 293.99 USD
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This is the starter motor for BMW E46 M3 2001-2006 is an OEM Valeo unit.

This item fits the following BMWs:
2001-2006 E46 BMW M3. M3 Convertible
2001-2002 Z3 BMW Z3 M Roadster Z3 M Coupe
2005-2008 E85 BMW Z4 M Roadster Z4 M Coupe
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BMW M52 Engine Crankshaft Position Sensor
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Delphi - Corporate Logo
T#:373958
Part#: 12141709616
In Stock
$ 97.99

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

$ 94.99 USD
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$ 94.99 USD
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OEM Bosch Alternator AL0703N - 120A - E38 E39 E46 E53 Z3
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Bosch - Corporate Logo
T#:583735
Part#: 12317501690
In Stock
$ 526.99

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

$ 415.99 USD
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$ 415.99 USD
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If your car has died on the side of the road from a dead battery and you notice flickering or low powered headlights, it's likely your alternator failing. To be sure you are getting a high-quality part with a long life-span, choose this OEM Bosch Alternator. This is a brand new OEM replacement for BMW part # 12317501690.

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!

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OEM Bosch Alternator - E46 M3, Z3 S54
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Bosch - Corporate Logo
T#:370775
Part#: 12317831436
In Stock
$ 512.99

This product was last offered at the strikethrough price on
03-30-2026

$ 322.99 USD
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$ 322.99 USD
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A replacement Bosch alternator for the 2001-2006 M3. Bosch is an original equipment supplier to BMW, and is the finest and most recognized German brand of alternator available. The Original BMW alternator sells for over double! Buy only the best alternator for your BMW -- buy a Bosch alternator. This is an OEM replacement for BMW part # 12317831436.

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!

A $80.00 refundable core charge must be applied to this alternator. Upon receipt of your rebuildable alternator core, you will be refunded the core charge. 

This item fits the following BMWs:
2001-2006 E46 BMW M3, M3 Convertible
2001-2002 Z3 BMW M Roadster M Coupe

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Camshaft Position Sensor, Intake Camshaft 12147539165
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Genuine BMW - Corporate Logo
T#:12480
Part#: 12147539165
In Stock
9% off MSRP $ 228.86

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 208.24 USD
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9% off MSRP
$ 228.86

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$ 208.24 USD
Free Shipping

Located on the intake side of the cylinder head, this sensor relays the position of the camshaft to the computer in order to determine proper ignition timing. When this sensor fails the engine will generally log a fault code and may place the vehicle into "limp" mode. When this happens it is advised to stop driving the vehicle and address the issue immediately as premature wear or long term damage to the engine is possible.

When doing any sort of repair or maintenance there is no replacement for genuine factory parts. Turner Motorsport carries the Genuine BMW brand with pride and has the parts you need to complete your next project with confidence.

OE BMW reference number: 12147539165
 

We also carry a this sensor with the required o ring Here

This part fits the following BMWs:
1998 - 2004 E39 Touring 525i 528i 
1996 - 2004 E39 Sedan 525i 528i 530i  
1999 - 2006 E46  323i 323ci 325i 325ci 325xi 328i 328ci 328xi 330i 330ci 330xi 

 

 

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DSC Pressure Sensor
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URO - Corporate Logo
T#:567281
Part#: 34521164458
In Stock
$ 152.99 USD
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$ 152.99 USD
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This sensor is attached to the brake master cylinder
FAE Exhaust Camshaft Position Sensor
Sensor for the exhaust camshaft
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FAE - Corporate Logo
T#:1196088
Part#: 13627796054
In Stock
$ 74.99 USD
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$ 74.99 USD
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Located on rear of the cylinder head, sensing the exhaust cam