The 3rd generation Tesla DC-DC converter converts high-voltage pack power down to the 12 V system that supports lighting, control modules, pumps, relays, and accessories. When this unit weakens or fails, the 12 V battery is no longer charged correctly, leading to warning messages, low-voltage shutdowns, and no-start conditions. This OEM-style replacement for part number 1028664-00-E restores proper 12 V charging performance in later Tesla Model S vehicles.
Each 3rd generation DC-DC converter 1028664-00-E we supply is an OEM Tesla unit that has been bench-tested under load by our EV technicians. The converter is energized with simulated pack voltage on the high-voltage side and loaded on the 12 V output to confirm stable regulation, proper current capacity, and galvanic isolation before shipment.
| Part Number | 1028664-00-E (3rd generation DC-DC converter, Tesla Model S) |
| Function | Converts high-voltage traction pack DC to regulated 12 V DC to support the LV electrical system and charge the 12 V battery. |
| Vehicle Application | Tesla Model S vehicles equipped with DC-DC converter 1028664-00-E. Confirm by part label or VIN before ordering. |
| Electrical | High-voltage DC input from the traction battery; isolated, regulated 12 V DC output sized for OEM LV loads and battery charging. |
| Cooling / Housing | Sealed aluminum housing mounted in the vehicle’s HV electronics area, designed to integrate with the factory thermal management strategy. |
| Installation | Bolt-in replacement; requires high-voltage lockout, correct torque on HV and LV connections, and post-install function and isolation checks. |
| Condition | Cleaned and bench-tested OEM unit, inspected for connector damage, corrosion, and heat-related defects. |
Gruber Motor Company can supply this 3rd generation DC-DC converter as a stand-alone component or install it as part of a complete high-voltage / low-voltage diagnostic and repair package at our Phoenix facility. If you’re unsure whether your Model S uses 1028664-00-E, contact us with your VIN and a photo of the existing converter and we can confirm fitment.
After replacing a DC-DC converter, always load-test or replace the 12 V battery and check all major grounds and high-current LV connections. Weak batteries and poor connections are common root causes of repeated DC-DC converter failures and persistent warning messages.
Our Tesla specialists routinely diagnose Model S DC-DC converter and 12 V charging issues. For help confirming part numbers, interpreting fault codes, or planning an installation, call 623.433.8500 or email our service team with your VIN and photos of your existing converter.
