The 2021 Ram 4000 has 7 electrical parts with verified fitment on this page — 4 part types and 5 brands, covering both the 5.7L V8 and the 6.4L V8. Each part includes a manufacturer part number and application notes.
On the 2021 Ram 4000, the electrical system covers charging, starting and the sensors and modules the vehicle relies on, from alternator and starter to oxygen sensors. 6 parts of the 7 listed are Battery (3 parts), Keyless Entry Remote (2 parts) and Alternator / Generator (1 part). The other 1 part type covers the remaining 1 part.
The 2021 Ram 4000 was sold with both the 5.7L V8 and the 6.4L V8. 6 parts fit every engine; the other 1 is engine-specific. Each part shows which engine(s) it fits.
The most listed brands for 2021 Ram 4000 electrical parts are DORMAN (3 parts), VALEO (1 part) and BOSCH (1 part), plus 2 more brands.
Each part number listed for the 2021 Ram 4000 opens a page with every vehicle that part fits.
Alternator / Generator
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| VALEO Fits: all 2021 4000 engines | 501829 | 🇲🇽 MX | 220 Amps | View on Amazon |
This table covers the alternators that charge the battery and run the electrical load. Typical signs include dim lights at idle, a battery lamp, or a growl from the charging pulley. Load-test the battery and inspect the belt and grounds — a bad ground mimics a failed alternator.
One part is listed for the 2021 Ram 4000 — VALEO 501829.
Battery
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| BOSCH Fits: all 2021 4000 engines | S6587B | 🇲🇽 MX | AGMAGM | View on Amazon |
| DEKA Fits: all 2021 4000 engines | 9A94R | 🇲🇽 MX | IntimidatorAGM | View on Amazon |
| MOTORCRAFT Fits: 5.7L V8 | BAGM94RH7800E | 🇲🇽 MX | View on Amazon |
This table covers the batteries listed by group size and specification. Typical signs include slow cranking, a battery lamp, or a no-start after the vehicle sat overnight. Confirm group size and terminal layout in the notes. Clean the posts and the ground before condemning the battery.
3 Battery parts for the 2021 Ram 4000 come from 3 brands — BOSCH, DEKA and MOTORCRAFT. 2 parts fit every engine; the other 1 is engine-specific.
Part numbers include BOSCH S6587B, DEKA 9A94R and MOTORCRAFT BAGM94RH7800E.
Keyless Entry Remote
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DORMAN Fits: all 2021 4000 engines | 99772ST | 🇲🇽 MX | Requires Locksmith Or Additional Scan Tool To Program | View on Amazon |
| DORMAN Fits: all 2021 4000 engines | 99770ST | 🇲🇽 MX | Requires Locksmith Or Additional Scan Tool To Program | View on Amazon |
This table covers the key fobs that lock, unlock and start the vehicle.
DORMAN supplies both parts for the 2021 Ram 4000. All of them fit every engine offered in the 2021 4000.
Part numbers include DORMAN 99772ST and DORMAN 99770ST.
Parking Aid Sensor
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| DORMAN Fits: all 2021 4000 engines | 684102 | 🇲🇽 MX | Fits Rear | View on Amazon |
This table covers the ultrasonic park-aid sensors in the bumper. 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.
One part is listed for the 2021 Ram 4000 — DORMAN 684102.
Buying Electrical Parts for a 2021 Ram 4000
On this vehicle, the electrical system covers charging, starting and the sensors and modules the vehicle relies on, from alternator and starter to oxygen sensors.
- Match the engine first. Some electrical 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, clean or renew the battery terminals and grounds with any charging-system repair.
- Cross-reference the manufacturer part number against your old part or a service-manual listing.
Start with the largest groups on this page: Battery and Keyless Entry Remote .
Frequently Asked Questions
How many electrical parts fit the 2021 Ram 4000?
Our catalog currently lists 7 electrical parts for the 2021 Ram 4000 across 4 subcategories and 5 brands, covering both the 5.7L V8 and the 6.4L V8. Each part is matched to the engine(s) it fits.
Do electrical parts differ between 2021 Ram 4000 engines?
Some do. 6 parts fit 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 problems on a 2021 Ram 4000?
Common symptoms include slow cranking on cold mornings, a battery light that flickers, dim lights at idle, or a check-engine code pointing at a sensor circuit. 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, clean or renew the battery terminals and grounds with any charging-system repair.
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 Ram 4000 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 Ram 4000?
First match the engine — each row shows which engine(s) the part fits. Then test before replacing — a failed alternator and a bad ground can look identical, and sensors are frequently condemned for wiring faults. The notes column carries position and trim qualifiers where they apply.
Other Parts for the 2021 Ram 4000
Electrical Parts for Other Ram 4000 Years
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