Chevrolet / Buick 4-Pin Female Waterproof Fan Motor Wire Harness Connector – OEM 12191399 / 12191387
Direct OEM-specification replacement for the Delphi 4-pin female waterproof wire harness connector used on cooling fan motors across Chevrolet and Buick GM platforms. Cross-references Delphi / GM OEM part numbers 12191399 and 12191387. Black nylon housing with waterproof sealing — designed for underbonnet cooling fan motor applications on GM Ecotec and LT engine platforms where the connector must carry the full fan motor current in a high-heat, high-vibration environment.
The 4-pin fan motor connector on Chevrolet and Buick vehicles is used on variable-speed cooling fans that are controlled by the ECM via a PWM (pulse-width modulation) signal. Unlike simple 2-pin on/off fan connectors, the 4-pin connector carries both the high-current motor supply and the low-current PWM control signal. A failed connector causes the cooling fan to stop operating or to run at a fixed speed, leading to engine overheating in traffic or A/C performance degradation at low vehicle speeds.
| OEM Number | Application |
|---|---|
| 12191399 | Delphi 4-pin fan motor connector (primary) |
| 12191387 | Delphi 4-pin fan motor connector (alternate) |
| Pin | Function | Failure Symptom if Open |
|---|---|---|
| 1 | Fan motor power supply (12V, high-current) | Fan not operating, engine overheating |
| 2 | Fan motor ground (high-current) | Fan inoperative |
| 3 | PWM speed control signal from ECM | Fan runs at fixed speed or not at all |
| 4 | Fan speed feedback / tachometer signal | ECM loses fan speed data, cooling fault |
| Attribute | Detail |
|---|---|
| Pin Count | 4-Pin |
| Gender | Female |
| Housing Material | Nylon, black |
| Sealing | Waterproof |
| OEM Part Numbers | 12191399 / 12191387 |
| Applications | Variable-speed cooling fan motor, radiator fan, condenser fan |
| Compatible Models | Chevrolet Cruze / Malibu / Equinox / Trax; Buick Excelle GT / Regal / LaCrosse |
| Terminal Included | Yes |
Q: My Chevrolet Cruze is overheating in traffic but the fan runs at highway speed — could it be the connector?
A: Yes. A failed PWM signal pin (pin 3) on the 4-pin fan connector causes the fan to run at a fixed low speed instead of ramping up in traffic. The fan appears to work but cannot cool the engine at low vehicle speeds. Inspect the connector (OEM 12191399) before replacing the fan motor or ECM.
Q: Are terminals included?
A: Yes, terminals are included with all variants.
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4 Pin Connectors
