22 Electrical switch & relay parts are listed for the 2021 Mazda CX-5, in 7 part types, covering both the 2.5L L4 and the 2.5L L4 Turbocharged. Each one has a brand, a manufacturer part number and notes that say where it fits.
On the 2021 Mazda CX-5, the switch and relay system covers the switches, relays and flashers that route power to everything the driver touches. Most of the listed parts are Brake Light Switch (8 parts), A/C Refrigerant Pressure Switch (4 parts) and A/C Compressor Relay (3 parts). The other 4 part types cover the remaining 7 parts.
The 2021 Mazda CX-5 was sold with both the 2.5L L4 and the 2.5L L4 Turbocharged. Every part on this page is engine-specific. Each part shows which engine(s) it fits.
12 brands supply electrical switch & relay parts for the 2021 Mazda CX-5, led by STANDARD MOTOR PRODUCTS (8 parts), HOLSTEIN (2 parts) and UAC (2 parts), plus 9 more brands. Quality grades include Economy and Standard Replacement.
A "Popular" badge means the source catalog flagged the part as frequently chosen for the 2021 Mazda CX-5. 2 parts have it, including ULTRA-POWER SLS355 (Brake Light Switch) and STANDARD MOTOR PRODUCTS SLS355 (Brake Light Switch). Each part number opens a page with every vehicle that part fits.
A/C Compressor Relay
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| HOLSTEIN Fits: 2.5L L4 | 2RSW0006 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Control Relay | View on Amazon |
| STANDARD MOTOR PRODUCTS Fits: 2.5L L4 | RY805T | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | T-Series | View on Amazon |
| STANDARD MOTOR PRODUCTS Fits: 2.5L L4 | RY805 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Functions: Multi-Function Relay | View on Amazon |
This table covers the relays that control the A/C Compressor circuit. Typical signs include a click with no action, or a circuit that works only when you swap in a known-good relay. Swap with an identical relay in the fuse box before buying — it is the fastest test there is.
3 A/C Compressor Relay parts are listed for the 2021 Mazda CX-5, from STANDARD MOTOR PRODUCTS and HOLSTEIN.
Part numbers include HOLSTEIN 2RSW0006, STANDARD MOTOR PRODUCTS RY805T and STANDARD MOTOR PRODUCTS RY805.
A/C Refrigerant Pressure Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| FACET Fits: 2.5L L4 | 250073 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon | |
| FOUR SEASONS Fits: 2.5L L4 | 20994 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Pressure Switch | View on Amazon |
| JAPANESE OE Fits: 2.5L L4 | 3ACP0030 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Sensata | View on Amazon |
| UAC Fits: 2.5L L4 | SW10087C | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Pressure Transducer | View on Amazon |
This table covers the pressure switches on the A/C circuit. Typical signs include a function that works intermittently, or a click without the accessory coming on. Inspect the connector behind the switch; heat-damaged terminals will kill the new part too.
4 A/C Refrigerant Pressure Switch parts are listed for the 2021 Mazda CX-5, from FACET, FOUR SEASONS, JAPANESE OE and 1 other brand.
Listed part numbers: FACET 250073, FOUR SEASONS 20994 and JAPANESE OE 3ACP0030, plus the other parts above.
A/C System Relay
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| UAC Fits: 2.5L L4 | RE8415 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon |
This table covers the relays that control the A/C System circuit. Typical signs include a click with no action, or a circuit that works only when you swap in a known-good relay. Swap with an identical relay in the fuse box before buying — it is the fastest test there is.
One part is listed for the 2021 Mazda CX-5 — UAC RE8415.
Body Wiring Harness Relay
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| STANDARD MOTOR PRODUCTS Fits: 2.5L L4 | RY805T | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | T-Series | View on Amazon |
| STANDARD MOTOR PRODUCTS Fits: 2.5L L4 | RY805 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Functions: Multi-Function Relay | View on Amazon |
This table covers the relays that control the Body Wiring Harness circuit. Typical signs include a click with no action, or a circuit that works only when you swap in a known-good relay. Swap with an identical relay in the fuse box before buying — it is the fastest test there is.
STANDARD MOTOR PRODUCTS supplies both parts for the 2021 Mazda CX-5.
Listed part numbers: STANDARD MOTOR PRODUCTS RY805T and STANDARD MOTOR PRODUCTS RY805.
Brake Light Switch
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| ULTRA-POWER Popular Fits: 2.5L L4 | SLS355 | 🇺🇸 US 🇨🇦 CA | View on Amazon | |
| AUTOTECNICA Fits: 2.5L L4 | MA1319181 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon | |
| DORMAN Fits: 2.5L L4 | 920493 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon | |
| STANDARD MOTOR PRODUCTS Fits: 2.5L L4 | SLS355T | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | T-SeriesColor/Finish: Blue, Gray | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| STANDARD MOTOR PRODUCTS Popular Fits: 2.5L L4 | SLS355 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Color/Finish: Black, Blue | View on Amazon |
| BECK/ARNLEY Fits: 2.5L L4 | 2012742 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon | |
| ROSTRA Fits: 2.5L L4 | 620296 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon | |
| WELLS Fits: 2.5L L4 | 1S8007 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon |
This table covers the pedal-mounted switch that turns on the brake lamps. Typical signs include a function that works intermittently, or a click without the accessory coming on. Inspect the connector behind the switch; heat-damaged terminals will kill the new part too.
8 Brake Light Switch parts are listed for the 2021 Mazda CX-5, from STANDARD MOTOR PRODUCTS, ULTRA-POWER, AUTOTECNICA and 4 other brands. ULTRA-POWER SLS355 carries the "Popular" badge.
In the Economy grade, ULTRA-POWER, AUTOTECNICA, DORMAN and 1 other brand supply 4 parts: the catalog's value-priced group. A representative part number is ULTRA-POWER SLS355.
The Standard Replacement section lists 4 options from STANDARD MOTOR PRODUCTS, BECK/ARNLEY, ROSTRA and 1 other brand — built to original-equipment specification. STANDARD MOTOR PRODUCTS SLS355 is listed in this group.
Part numbers include ULTRA-POWER SLS355, AUTOTECNICA MA1319181 and DORMAN 920493, among others listed above.
Fog / Driving Lamp Relay
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| HOLSTEIN Fits: 2.5L L4 | 2RSW0006 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon | |
| STANDARD MOTOR PRODUCTS Fits: 2.5L L4 | RY805T | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | T-Series | View on Amazon |
| STANDARD MOTOR PRODUCTS Fits: 2.5L L4 | RY805 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Functions: Multi-Function Relay | View on Amazon |
This table covers the relays that control the Fog / Driving Lamp circuit. Typical signs include a click with no action, or a circuit that works only when you swap in a known-good relay. Swap with an identical relay in the fuse box before buying — it is the fastest test there is.
3 Fog / Driving Lamp Relay parts are listed for the 2021 Mazda CX-5, from STANDARD MOTOR PRODUCTS and HOLSTEIN.
Listed part numbers: HOLSTEIN 2RSW0006, STANDARD MOTOR PRODUCTS RY805T and STANDARD MOTOR PRODUCTS RY805.
Fuel Pump / Circuit Opening Relay
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| WELLS Fits: 2.5L L4 | 1R3684 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon |
This table covers the relays that control the Fuel Pump / Circuit Opening circuit. Typical signs include a click with no action, or a circuit that works only when you swap in a known-good relay. Swap with an identical relay in the fuse box before buying — it is the fastest test there is.
One part is listed for the 2021 Mazda CX-5 — WELLS 1R3684.
Buying Electrical Switch & Relay Parts for a 2021 Mazda CX-5
On this vehicle, the switch and relay system covers the switches, relays and flashers that route power to everything the driver touches.
- Match the engine first. Every electrical switch & relay part here is engine-specific; each row shows which engine(s) it fits.
- Read the notes on each row for position, trim and spec qualifiers before you order.
- Where labor overlaps, inspect the connector terminals behind any failed switch — heat damage there will kill the new part too.
- Cross-reference the manufacturer part number against your old part or a service-manual listing.
Start with the largest groups on this page: Brake Light Switch and A/C Refrigerant Pressure Switch .
Frequently Asked Questions
How many electrical switch & relay parts fit the 2021 Mazda CX-5?
Our catalog currently lists 22 electrical switch & relay parts for the 2021 Mazda CX-5 across 7 subcategories and 12 brands, covering both the 2.5L L4 and the 2.5L L4 Turbocharged. Each part is matched to the engine(s) it fits.
Do electrical switch & relay parts differ between 2021 Mazda CX-5 engines?
Yes. Every electrical switch & relay part on this page is engine-specific. Each row shows which engine(s) it fits — use the filter at the top to hide the rest. If you're unsure which engine you have, check the emissions label under the hood or the 8th character of your VIN.
What are the signs of electrical switch & relay problems on a 2021 Mazda CX-5?
Common symptoms include accessories that work intermittently, a click without action, or one function dead while its fuse tests fine. If you notice any of these, identify the affected subcategory above and cross-reference the part numbers listed.
What should I replace at the same time?
Where labor overlaps, inspect the connector terminals behind any failed switch — heat damage there will kill the new part too.
What do the market flags (US, CA, MX) on each part mean?
They show the market for which the manufacturer published application data for that part — where the vehicle was first sold, not where the part was made. If your 2021 Mazda CX-5 was originally sold in the US, the safest choice is a part marked for the US market.
How do I make sure a part fits my 2021 Mazda CX-5?
First match the engine — each row shows which engine(s) the part fits. Then swap a suspect relay with an identical known-good one from the fuse box before buying — it is the fastest diagnostic there is. The notes column carries position and trim qualifiers where they apply.
Other Parts for the 2021 Mazda CX-5
Electrical Switch & Relay Parts for Other Mazda CX-5 Years
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