The 2021 Isuzu NPR has 2 electrical switch & relay parts with verified fitment on this page — 2 part types and 1 brand, covering both the 5.2L L4 DIESEL Turbocharged and the 6.6L V8. Each part includes a manufacturer part number and application notes.
On the 2021 Isuzu NPR, the switch and relay system covers the switches, relays and flashers that route power to everything the driver touches. All 2 listed parts are A/C Compressor Relay (1 part) and A/C Trinary Switch (1 part).
The 2021 Isuzu NPR was sold with both the 5.2L L4 DIESEL Turbocharged and the 6.6L V8. 1 part fits every engine; the other 1 is engine-specific. Each part shows which engine(s) it fits.
Every electrical switch & relay part listed for the 2021 Isuzu NPR comes from FOUR SEASONS.
Each part number listed for the 2021 Isuzu NPR opens a page with every vehicle that part fits.
A/C Compressor Relay
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| FOUR SEASONS Fits: 6.6L V8 | 36141 | 🇺🇸 US 🇨🇦 CA | with 10S17F CompressorRecommended To Eliminate Compressor Damage On Vehicles with Low Mount Compressor | 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.
One part is listed for the 2021 Isuzu NPR — FOUR SEASONS 36141.
A/C Trinary Switch
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| FOUR SEASONS Fits: all 2021 NPR engines | 20944 | 🇺🇸 US 🇨🇦 CA | Pressure Switch | View on Amazon |
This table covers the A/C Trinary 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: FOUR SEASONS 20944.
Buying Electrical Switch & Relay Parts for a 2021 Isuzu NPR
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: A/C Compressor Relay and A/C Trinary Switch .
Frequently Asked Questions
How many electrical switch & relay parts fit the 2021 Isuzu NPR?
Our catalog currently lists 2 electrical switch & relay parts for the 2021 Isuzu NPR across 2 subcategories and 1 brand, covering both the 5.2L L4 DIESEL Turbocharged and the 6.6L V8. Each part is matched to the engine(s) it fits.
Do electrical switch & relay parts differ between 2021 Isuzu NPR engines?
Some do. 1 part fits every engine; the other 1 is 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 2021 Isuzu NPR?
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 Isuzu NPR 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 Isuzu NPR?
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 Isuzu NPR
Electrical Switch & Relay Parts for Other Isuzu NPR Years
Switch vehicle or jump to a subcategory
Manufacturer names, model designations and part numbers are used for identification and fitment reference only. AutoFactsDB is an independent catalog and is not affiliated with, endorsed by, or sponsored by any vehicle manufacturer displayed on this page.