The 2018 Freightliner Cascadia has 12 electrical switch & relay parts with verified fitment on this page — 5 part types and 4 brands, covering all 5 engine options (11.9L L6 Turbocharged, 12.8L L6 DIESEL Turbocharged, 14.8L L6 DIESEL Turbocharged, 14.9L L6 DIESEL Turbocharged and 15.6L DIESEL Turbocharged). Each part includes a manufacturer part number and application notes.
On the 2018 Freightliner Cascadia, the switch and relay system covers the switches, relays and flashers that route power to everything the driver touches. 10 parts of the 12 listed are Oil Pressure Sender / Switch (5 parts), A/C Refrigerant Pressure Switch (4 parts) and Clutch Pedal Position / Starter Safety Switch (1 part). The other 2 part types cover the remaining 2 parts.
The 2018 Freightliner Cascadia was sold with 5 engines. 7 parts fit every engine; the other 5 are engine-specific. Each part shows which engine(s) it fits.
4 brands supply electrical switch & relay parts for the 2018 Freightliner Cascadia, led by DORMAN (6 parts), UAC (3 parts) and GPD (2 parts), plus 1 more brand.
Each part number listed for the 2018 Freightliner Cascadia opens a page with every vehicle that part fits.
A/C Refrigerant Pressure Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DORMAN Fits: all 2018 Cascadia engines | 9047890 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon | |
| UAC Fits: all 2018 Cascadia engines | SW11204C | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Binary Hpco/Lpco Switch | View on Amazon |
| UAC Fits: all 2018 Cascadia engines | SW10080C | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Pressure Transducer | View on Amazon |
| UAC Fits: all 2018 Cascadia engines | SW11189C | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | HPCO Switch | 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 2018 Freightliner Cascadia, from UAC and DORMAN. All of them fit every engine offered in the 2018 Cascadia.
Part numbers include DORMAN 9047890, UAC SW11204C and UAC SW10080C, among others listed above.
Clutch Pedal Position / Starter Safety Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DORMAN Fits: all 2018 Cascadia engines | 9015207 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon |
This table covers the Clutch Pedal Position / Starter 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.
This group shows a single part: DORMAN 9015207.
Headlamp Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DORMAN Fits: all 2018 Cascadia engines | 9015208 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon |
This table covers the column or dash switches that control the exterior 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.
This group shows a single part: DORMAN 9015208.
Oil Pressure Sender / Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DORMAN Fits: 11.9L L6 Turbocharged, 14.9L L6 DIESEL Turbocharged | 9045050 | 🇺🇸 US 🇨🇦 CA | View on Amazon | |
| DORMAN Fits: 12.8L L6 DIESEL Turbocharged, 14.8L L6 DIESEL Turbocharged, 15.6L DIESEL Turbocharged | 9047326 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Engine Code DD16Detroit Diesel engine | View on Amazon |
| GPD Fits: 11.9L L6 Turbocharged, 14.9L L6 DIESEL Turbocharged | 1815437 | 🇺🇸 US 🇨🇦 CA | View on Amazon | |
| GPD Fits: 12.8L L6 DIESEL Turbocharged, 14.8L L6 DIESEL Turbocharged, 15.6L DIESEL Turbocharged | 1815433 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | View on Amazon | |
| WALKER PRODUCTS Fits: 11.9L L6 Turbocharged, 14.9L L6 DIESEL Turbocharged | 10011004 | 🇺🇸 US 🇨🇦 CA | Cummins OEM # 4921517 | 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.
5 Oil Pressure Sender / Switch parts are listed for the 2018 Freightliner Cascadia, from DORMAN, GPD and WALKER PRODUCTS.
Part numbers include DORMAN 9045050, DORMAN 9047326 and GPD 1815437, among others listed above.
Power Window Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DORMAN Fits: all 2018 Cascadia engines | 9015203 | 🇺🇸 US 🇨🇦 CA 🇲🇽 MX | Front Left | 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.
One part is listed for the 2018 Freightliner Cascadia — DORMAN 9015203.
Buying Electrical Switch & Relay Parts for a 2018 Freightliner Cascadia
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 Freightliner Cascadia?
Our catalog currently lists 12 electrical switch & relay parts for the 2018 Freightliner Cascadia across 5 subcategories and 4 brands, covering all 5 engine options (11.9L L6 Turbocharged, 12.8L L6 DIESEL Turbocharged, 14.8L L6 DIESEL Turbocharged, 14.9L L6 DIESEL Turbocharged and 15.6L DIESEL Turbocharged). Each part is matched to the engine(s) it fits.
Do electrical switch & relay parts differ between 2018 Freightliner Cascadia engines?
Some do. 7 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 Freightliner Cascadia?
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 Freightliner Cascadia 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 Freightliner Cascadia?
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 Freightliner Cascadia
Electrical Switch & Relay Parts for Other Freightliner Cascadia Years
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