This page lists 46 electrical switch & relay parts for the 2018 Kia Optima, across 11 part types, covering all 4 engine options (1.6L L4 Turbocharged, 2.0L L4 ELECTRIC/GAS, 2.0L L4 Turbocharged and 2.4L L4). Every part shows its brand, manufacturer part number and fitment notes.
The switch and relay system on the 2018 Kia Optima covers the switches, relays and flashers that route power to everything the driver touches. The largest groups are Oil Pressure Sender / Switch (12 parts), A/C Refrigerant Pressure Switch (7 parts) and Brake Light Switch (6 parts). The other 8 part types cover the remaining 21 parts.
The 2018 Kia Optima was sold with 4 engines. 41 parts fit every engine; the other 5 are engine-specific. Each part shows which engine(s) it fits.
The most listed brands for 2018 Kia Optima electrical switch & relay parts are WELLS (15 parts), STANDARD MOTOR PRODUCTS (8 parts) and VEMO (4 parts), plus 13 more brands. Quality grades include Standard Replacement and Economy.
9 parts on this 2018 Kia Optima page carry a "Popular" badge — the source catalog's flag for options frequently chosen for this vehicle — including FOUR SEASONS 37324 (A/C Refrigerant Pressure Switch) and WELLS 1R3545 (Accessory Power Relay). Click any part number to see every vehicle that part fits.
A/C Pressure Safety Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VEMO Fits: all 2018 Optima engines | V52730034 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Hybrid EX or Hybrid Premium or Plug-In Hybrid EX | View on Amazon |
This table covers the A/C Pressure Safety switches. 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.
One part is listed for the 2018 Kia Optima — VEMO V52730034.
A/C Refrigerant Pressure Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| FOUR SEASONS Popular Fits: all 2018 Optima engines | 37324 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Pressure Switch | View on Amazon |
| UAC Popular Fits: all 2018 Optima engines | SW9969C | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Pressure Transducer | View on Amazon |
| FAMOUS BRAND Fits: all 2018 Optima engines | 1802492322 | 🇺🇸 US 🇨🇦 CA | Compressor Cut-Off Switch | View on Amazon |
| HYUNDAI Fits: all 2018 Optima engines | 977213K000 | 🇺🇸 US | Included with liquid line, suction tube, hose & tube assembly, pressure line assembly | View on Amazon |
| STANDARD MOTOR PRODUCTS Fits: all 2018 Optima engines | PCS195 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Low PressureCut-Off | View on Amazon |
| WELLS Fits: all 2018 Optima engines | 5S16579 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | CUT-OFF | View on Amazon |
| WELLS Fits: all 2018 Optima engines | 1S9347 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | 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.
7 A/C Refrigerant Pressure Switch parts for the 2018 Kia Optima come from 6 brands — WELLS, FOUR SEASONS, UAC and 3 other brands. The "Popular" part is FOUR SEASONS 37324. Every part fits all 4 engine options (1.6L L4 Turbocharged, 2.0L L4 ELECTRIC/GAS, 2.0L L4 Turbocharged and 2.4L L4).
This group includes FOUR SEASONS 37324, UAC SW9969C and FAMOUS BRAND 1802492322 and the remaining parts above.
A/C Thermo Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GPD Fits: all 2018 Optima engines | 1712994 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon |
This table covers the A/C Thermo switches. 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.
One part is listed for the 2018 Kia Optima — GPD 1712994.
Accessory Power Relay
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| WELLS Popular Fits: all 2018 Optima engines | 1R3545 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Connector Gender: MaleMounting Hardware Included: No | View on Amazon |
| HYUNDAI Fits: all 2018 Optima engines | 952302P020 | 🇺🇸 US | View on Amazon | |
| STANDARD MOTOR PRODUCTS Fits: all 2018 Optima engines | RY1850 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | In Engine Compartment | View on Amazon |
| WELLS Fits: all 2018 Optima engines | 1R3525 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Voltage: 12.0 2H | View on Amazon |
| WELLS Fits: all 2018 Optima engines | 1R2271 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | with 4 TerminalsSquare Type | View on Amazon |
This table covers the relays that control the Accessory Power 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.
5 Accessory Power Relay parts are listed for the 2018 Kia Optima, from WELLS, HYUNDAI and STANDARD MOTOR PRODUCTS. WELLS 1R3545 carries the "Popular" badge. All of them fit every engine offered in the 2018 Optima.
Listed part numbers: WELLS 1R3545, HYUNDAI 952302P020 and STANDARD MOTOR PRODUCTS RY1850, plus the other parts above.
Brake Light Switch
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DORMAN Fits: all 2018 Optima engines | 901267 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon | |
| HOLSTEIN Fits: all 2018 Optima engines | 2BLS0034 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| STANDARD MOTOR PRODUCTS Popular Fits: all 2018 Optima engines | SLS534 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon | |
| WELLS Popular Fits: all 2018 Optima engines | 1S12674 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon | |
| BECK/ARNLEY Fits: all 2018 Optima engines | 2012739 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon | |
| ROSTRA Fits: all 2018 Optima engines | 620051 | 🇺🇸 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.
6 Brake Light Switch parts for the 2018 Kia Optima come from 6 brands — DORMAN, HOLSTEIN, STANDARD MOTOR PRODUCTS and 3 other brands. The "Popular" part is STANDARD MOTOR PRODUCTS SLS534. Every part fits all 4 engine options (1.6L L4 Turbocharged, 2.0L L4 ELECTRIC/GAS, 2.0L L4 Turbocharged and 2.4L L4).
The Economy section lists 2 options from DORMAN and HOLSTEIN — the catalog's value-priced group. DORMAN 901267 is listed in this group.
In the Standard Replacement grade, STANDARD MOTOR PRODUCTS, WELLS, BECK/ARNLEY and 1 other brand supply 4 parts: built to original-equipment specification. A representative part number is STANDARD MOTOR PRODUCTS SLS534.
Part numbers include STANDARD MOTOR PRODUCTS SLS534, DORMAN 901267 and HOLSTEIN 2BLS0034, among others listed above.
Ignition Starter Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| WELLS Fits: all 2018 Optima engines | 1S16691 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | with Push Button Switch | View on Amazon |
This table covers the ignition switches that feed the starter 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.
One part is listed for the 2018 Kia Optima — WELLS 1S16691.
Multi-Function Relay
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| WELLS Fits: all 2018 Optima engines | 1R3525 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Voltage: 12.0 2H | View on Amazon |
| WELLS Fits: all 2018 Optima engines | 1R3545 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Connector Gender: MaleMounting Hardware Included: No | View on Amazon |
| WELLS Fits: all 2018 Optima engines | 1R2271 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | with 4 Blade TerminalsOmron Relay | View on Amazon |
This table covers the relays that control the Multi-Function 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 Multi-Function Relay parts for the 2018 Kia Optima come from WELLS. Every part fits all 4 engine options (1.6L L4 Turbocharged, 2.0L L4 ELECTRIC/GAS, 2.0L L4 Turbocharged and 2.4L L4).
Listed part numbers: WELLS 1R3525, WELLS 1R3545 and WELLS 1R2271.
Neutral Safety Switch / Range Sensor
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| SKP Fits: 1.6L L4 Turbocharged, 2.0L L4 Turbocharged, 2.4L L4 | SKNS666 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| STANDARD MOTOR PRODUCTS Fits: 1.6L L4 Turbocharged, 2.0L L4 Turbocharged, 2.4L L4 | NS666 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Finish: Cast Iron, PlasticMaterial: Plastic, Metal | View on Amazon |
| VEMO Fits: 2.0L L4 Turbocharged, 2.4L L4 | V52730044 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Fits or with Neutral Safety Switch | View on Amazon |
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VEMO Fits: 2.0L L4 ELECTRIC/GAS | V52730044 | 🇺🇸 US 🇨🇦 CA | Fits Hybrid EX or Hybrid Premium or Plug-In Hybrid EXor with Neutral Safety Switch | View on Amazon |
This table covers the Neutral Safety Switch / Range sensors. Typical signs include a warning lamp, a stored code, or a reading that drops out when the harness is wiggled. Inspect the connector and ground before replacing the sensor — wiring faults are often condemned as bad sensors.
4 Neutral Safety Switch / Range Sensor parts for the 2018 Kia Optima come from 3 brands — VEMO, SKP and STANDARD MOTOR PRODUCTS.
The Economy section: 1 option from SKP. SKP SKNS666 is listed in this group.
Standard Replacement: 2 parts, from STANDARD MOTOR PRODUCTS and VEMO. A representative part number is STANDARD MOTOR PRODUCTS NS666.
1 further part sits outside the graded sections, with the same engine-level match.
Listed part numbers: SKP SKNS666, STANDARD MOTOR PRODUCTS NS666 and VEMO V52730044, plus the other parts above.
Oil Pressure Sender / Switch
Economy
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| HOLSTEIN Fits: all 2018 Optima engines | 2OPS0001 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | with Light | View on Amazon |
| STANDARD MOTOR PRODUCTS Fits: all 2018 Optima engines | PS411T | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | T-Series | View on Amazon |
| UNITED MOTOR PRODUCTS Fits: all 2018 Optima engines | OPS189 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Long Designwith Light | View on Amazon |
| WALKER PRODUCTS Fits: all 2018 Optima engines | 2561059 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| BECK/ARNLEY Popular Fits: all 2018 Optima engines | 2011771 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | with Light | View on Amazon |
| HELLA Popular Fits: all 2018 Optima engines | 009600251 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | 1-Pin Connector | View on Amazon |
| STANDARD MOTOR PRODUCTS Popular Fits: all 2018 Optima engines | PS411 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Terminal Quantity: 1Terminal Type: Blade | View on Amazon |
| GPD Fits: all 2018 Optima engines | 1815237 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon | |
| HYUNDAI Fits: all 2018 Optima engines | 9475037100 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon | |
| ROSTRA Fits: all 2018 Optima engines | 501242 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Hybrid EX or Hybrid Premium or Plug-In Hybrid EX | View on Amazon |
| VEMO Fits: 2.0L L4 ELECTRIC/GAS | V53720147 | 🇺🇸 US 🇨🇦 CA | View on Amazon | |
| WELLS Fits: all 2018 Optima engines | 1S6857 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon |
This table covers the senders and switches that report oil pressure to the gauge or lamp. Typical signs include a lamp that stays on, or a gauge that never moves. Confirm power and ground at the connector before replacing the sender or switch.
12 Oil Pressure Sender / Switch parts for the 2018 Kia Optima come from 11 brands — STANDARD MOTOR PRODUCTS, HOLSTEIN, UNITED MOTOR PRODUCTS and 8 other brands. The "Popular" part is BECK/ARNLEY 2011771. 11 parts fit every engine; the other 1 is engine-specific.
The Economy section: 4 options from HOLSTEIN, STANDARD MOTOR PRODUCTS, UNITED MOTOR PRODUCTS and 1 other brand. HOLSTEIN 2OPS0001 is listed in this group.
Standard Replacement: 8 parts, from BECK/ARNLEY, HELLA, STANDARD MOTOR PRODUCTS and 5 other brands. A representative part number is BECK/ARNLEY 2011771.
Parking Brake Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| STANDARD MOTOR PRODUCTS Fits: all 2018 Optima engines | PBS144 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon |
This table covers the Parking Brake switches. 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.
This group shows a single part: STANDARD MOTOR PRODUCTS PBS144.
Power Window Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| WELLS Popular Fits: all 2018 Optima engines | 1S16524 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Front Right | View on Amazon |
| STANDARD MOTOR PRODUCTS Fits: all 2018 Optima engines | DWS2153 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Front Left | View on Amazon |
| WELLS Fits: all 2018 Optima engines | 1S16556 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Rear Left | View on Amazon |
| WELLS Fits: all 2018 Optima engines | 1S16479 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Front Leftwith Power Folding Mirrors | View on Amazon |
| WELLS Fits: all 2018 Optima engines | 1S16481 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Front Leftwithout Power Folding Mirrors | View on Amazon |
This table covers the switches that command each window motor. 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.
5 Power Window Switch parts for the 2018 Kia Optima come from 2 brands — WELLS and STANDARD MOTOR PRODUCTS. The "Popular" part is WELLS 1S16524. Every part fits all 4 engine options (1.6L L4 Turbocharged, 2.0L L4 ELECTRIC/GAS, 2.0L L4 Turbocharged and 2.4L L4).
This group includes WELLS 1S16524, STANDARD MOTOR PRODUCTS DWS2153 and WELLS 1S16556 and the remaining parts above.
Buying Electrical Switch & Relay Parts for a 2018 Kia Optima
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. Some electrical switch & relay parts fit every engine; others are 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: Oil Pressure Sender / Switch and A/C Refrigerant Pressure Switch .
Frequently Asked Questions
How many electrical switch & relay parts fit the 2018 Kia Optima?
Our catalog currently lists 46 electrical switch & relay parts for the 2018 Kia Optima across 11 subcategories and 16 brands, covering all 4 engine options (1.6L L4 Turbocharged, 2.0L L4 ELECTRIC/GAS, 2.0L L4 Turbocharged and 2.4L L4). Each part is matched to the engine(s) it fits.
Do electrical switch & relay parts differ between 2018 Kia Optima engines?
Some do. 41 parts fit every engine; the other 5 are engine-specific. Each row (and the filter at the top) shows which. 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 2018 Kia Optima?
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 2018 Kia Optima 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 2018 Kia Optima?
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 2018 Kia Optima
Electrical Switch & Relay Parts for Other Kia Optima Years
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