12V 1.4KW 12T Starter Motor 77ST155 for Geely

Overview of the 77ST155 Starter Motor

The 77ST155 is a 12V, 1.4 kW starter motor supplied for Geely. A reduction gearset between motor and pinion keeps the body compact while still delivering the cranking torque the engine needs.

Because the motor is only used in short bursts, heat builds up quickly and escapes slowly. A starter that has worked for years in traffic or on site will show heat-hardened resin, shortened brushes and a pitted solenoid contact long before the windings fail.

Key Specifications

• Rated voltage: 12V
• Rated output: 1.4 kW
• Pinion: 12 teeth
• Type: reduction gear starter with pre-engaged solenoid
• Application: Geely
• Net weight: approximately 2.2 kg
• Condition: new, direct replacement for the original unit

A 12V 1.4 kW rating is the output the motor can hold while cranking, not a peak figure. It is sized so the engine reaches starting speed on the first or second revolution, which is what makes a healthy start feel immediate.

The reduction gearset lets the motor run at high speed while the pinion turns slowly with high torque, which is why the unit stays compact enough for a crowded engine bay.

Reference Numbers and Cross References

The reference family for this starter covers the numbers listed here:

• 416003
• 77ST155
• STQ9947YJ
• STQ9947BA
• STQ9947BS
• 000001016020979
• STQ9947RN
• STQ9947WA

Several numbers in this list belong to complete starter assemblies while others refer to the motor only. A visual check of the drive end protects against the most common ordering error. This starter is listed with 8 references in total.

Where This Starter Is Used

The unit is listed for Geely. Because manufacturers changed starter suppliers during the production run, the safest check is the number stamped on the starter body, not the model year alone. On Geely installations, access to the 77ST155 usually decides how long the job takes.

A mismatched pinion is the most common cause of a starter that engages noisily or refuses to mesh. Compare the tooth count before fitting, not after.

Why These Starters Fail

The brush plate is the second common failure point. Brushes shorten gradually, spring pressure falls, and contact becomes intermittent. Cranking speed drops a little every week until the engine refuses to start on a cold morning.

Oil or coolant mist from a leaking seal finds its way into the drive end housing, mixes with carbon dust and forms a conductive paste. The starter then arcs internally and fails early, whatever its mileage. This applies in particular to the 77ST155 supplied for Geely.

Fault Symptoms

• Click from the solenoid with no rotation, sometimes clearing on a second attempt
• Cranking that has become slower over several weeks
• Grinding as the pinion meets the ring gear
• Starter that keeps running after the key is released
• Intermittent no-crank that appears when the engine bay is hot

A cranking voltage test separates the starter from the rest of the circuit. If battery voltage stays healthy at the terminals but drops sharply at the starter stud, the cable or the connection is at fault rather than the motor. Owners of Geely should treat the 77ST155 reference list as a starting point, not the final answer.

Before You Fit the Replacement

• Condition of the old pinion and ring gear before the new unit goes in
• Main cable continuity and the condition of the lug at the starter stud
• Battery voltage while cranking, measured at the battery posts
• Mounting face cleanliness and bolt condition
• That the replacement terminal layout matches the original harness

Most comebacks after a starter replacement trace back to something that was not checked before the unit went on: a tired battery, a corroded earth or a chipped ring gear. Ten minutes with a multimeter and a torch prevents the second repair.

Fitting the Replacement

Disconnect the battery negative terminal, remove the intake parts that restrict access, then disconnect the main cable and the solenoid signal connector. Support the starter before removing the mounting bolts.

Inspect the ring gear teeth and the mounting face, then fit the replacement and torque the bolts evenly. Reconnect the main cable and signal wire, crank the engine for a moment and listen for clean engagement without a screech or grind. The 77ST155 ships with its solenoid fitted, so no parts have to be transferred from the old unit.

Quality Control and Supply from Hejian Nuojin Auto Parts Co., Ltd.

Hejian Nuojin Auto Parts Co., Ltd. manufactures starter and alternator components for the aftermarket. Every unit is bench tested for no-load current draw, solenoid pull-in and release voltage, pinion throw and running noise before packing.

Common references are kept in stock for fast dispatch, volume orders are delivered in around 30 days and each starter carries a one-year warranty against manufacturing defects.

Frequently Asked Questions

Should the ring gear be replaced at the same time?

Only if teeth are chipped, worn to a step or missing. Inspect the ring gear through the starter aperture before fitting the new unit.

Why does the starter click but not turn?

Most often the battery is low, a terminal is corroded or the solenoid contact is burnt. Measure battery voltage while the key is turned; a healthy battery that still gives only a click points to the solenoid.

Does this starter come with the solenoid?

The starter is supplied as a complete assembly including the solenoid. Reuse the original mounting bolts if they are in good condition.

Why does the starter work cold but fail when hot?

Heat raises solenoid resistance and reduces brush spring pressure. Both effects build up gradually and appear first on a hot restart.

Applicable Models Model Years Engine Code Displacement Power Body Type

Model: Geely BINYUE 1.5 T Years: 2020–Onwards Engine Code: JLH-3G15TD Displacement: 1477 cc Power: 110 kW Body Type: SUV

Model: Geely BOYUE PRO 1.5 Years: 2019–Onwards Engine Code: JLH-3G15TD Displacement: 1477 cc Power: 130 kW Body Type: SUV