Molex 34566-0803 - 80 way housing

Molex 34566-0803 MX123 Series 80-Way Sealed Female ECU Receptacle Housing (Option H, Gray)

Maintain absolute data continuity, clean voltage distribution, and total environmental protection at your vehicle’s central processor with this genuine Molex 34566-0803 80-way female automotive connector housing. Meticulously engineered by Molex as part of their elite MX123 powertrain interconnect system, this high-performance 80-pin socket block features the specific **Keying Option H** polarization profile and is fitted with a highly visible **Gray** Terminal Position Assurance (TPA) lock mechanism. Built to safely withstand harsh, long-term engine-vibration profiles, it delivers an exceptionally robust interface for sensitive low-voltage control circuits.

The 34566-0803 housing is a vital component in modern automotive powertrain infrastructure. It is widely relied upon as the main engine loom wiring harness interface for heavy-duty **Engine Control Units (ECUs) and Powertrain Control Modules (PCMs)** across a broad array of global automotive and commercial vehicle platforms. Positioned directly in high-stress under-hood zones or firewall mount locations, these multi-pin plugs are consistently exposed to severe thermal cycles, moisture, and chemical fluids. Over time, or during intensive diagnostic handling and engine rebuilds, the factory lever locks or internal pin pathways can wear out or suffer fracture damage. This authentic replacement shell allows Master Technicians and custom motorsport loom fabricators to cleanly de-pin a damaged factory module plug and transfer the existing lines into a fresh, robust housing, avoiding the massive cost and labor of an entirely new engine wiring loom overlay.

### Key Features & Technical Specifications:

* **Genuine Molex Interconnect Integrity:** Guarantees precise mechanical dimensions, zero-tolerance terminal alignment, and perfect insertion force dynamics. Prevents terminal backing and intermittent connection drops common with unbranded replicas.

* **Ultra-High Density MX123 Array:** Compact 4-row layout on a clean 2.54mm pitch spacing, combining an advanced internal matte-grommet seal system to pack maximum wiring capacity into a small footprint.

* **Keying Option H (Gray TPA):** Features distinct physical indexing keyways to completely eliminate the threat of accidental cross-mating on dense multi-plug module bays.

* **IP67 / IPx9K Waterproof Defence:** Engineered with an internal high-durability silicone perimeter seal and a unified rear matte seal that firmly tightly compresses around individual wires, locking out high-pressure road spray, humidity, oil vapors, and road salt.

* **Audible Secondary Lock Assurance:** Outfitted with an integrated lever-lock assist mechanism and a secondary TPA lock clip, confirming with distinct tactile and visual feedback that contacts are perfectly seated and guarded against terminal fretting.

In stock at our centralized UK distribution facility and available for immediate packing and dispatch worldwide to keep your workshop or electronics assembly line moving. Bulk B2B tier pricing scales automatically directly inside your shopping cart at checkout.