12V 1.2KW 9T Starter Motor STD2902BA for Cadillac Chevrolet GMC Isuzu

Overview of the STD2902BA Starter Motor

The STD2902BA starter motor is a 12V, 1.2 kW unit built for Cadillac Chevrolet GMC Isuzu. It is a reduction-gear starter with a pre-engaged solenoid, assembled to the original mounting flange and terminal positions so it fits without adapters or wiring changes.

The starter carries the full cranking current through its brushes and solenoid contact, so every start costs a little material. That is why the unit is normally replaced once, at the end of a long service life, rather than repaired repeatedly.

Key Specifications

• Rated voltage: 12V
• Rated output: 1.2 kW
• Pinion: 9 teeth
• Type: reduction gear starter with pre-engaged solenoid
• Application: Cadillac Chevrolet GMC Isuzu
• Net weight: approximately 2.95 kg
• Condition: new, direct replacement for the original unit

A 12V 1.2 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 starter is supplied against the following references, which help identify it against the unit already fitted to the vehicle:

• 112902
• 10465463
• 12560672
• 10465548
• 10465561
• 10465579
• 12563908
• 8000045
• 9000842
• 9000854
• 9000873
• 9000896
• 9000906
• 9000939
• 12564111
• 12568051

Where the label on the old starter has corroded, compare the pinion teeth, the mounting flange and the terminal bracket with the photographs before ordering. The number on the original unit is the reliable identifier. This starter is listed with 16 references in total.

Where This Starter Is Used

This starter family was fitted to a range of Cadillac applications, and the part number changed as engines and flywheels were revised. The unit listed here covers the references above and is a direct replacement where those numbers match. Fitting the STD2902BA correctly takes less time than diagnosing the original fault.

When ordering for a fleet, quote the starter number from each vehicle rather than a single model reference; mixed build dates are common and the starter changed with them.

What Wears Out First

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.

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. The STD2902BA ships with its solenoid fitted, so no parts have to be transferred from the old unit.

What to Look For

• 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. Where a STD2902BA has been replaced before, check that the fitted unit still matches the reference list.

Checks Before Installation

• Battery capacity under load, not just open-circuit voltage
• Terminal clamps and the main cable lug for corrosion or heat marks
• Earth strap between engine and chassis
• Ring gear teeth, visible through the starter aperture
• Key switch and signal wire voltage at the solenoid terminal

Fitting a new starter onto a worn ring gear or a marginal battery shortens its life. Check the simple items first, then fit the unit once and correctly.

Fitting Guidance

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.

After fitting, confirm the pinion returns freely and the cables are clear of the exhaust. Crank once before the first drive, then re-check the main terminal for tightness after the first heat cycle. For the STD2902BA, the practical check is the number stamped on the housing.

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.

Standard references are held as spot goods, volume orders are delivered in around 30 days, and every unit 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.

How do I confirm the starter matches my vehicle?

Compare the original part number first, then check the pinion tooth count and the terminal connector layout. The vehicle model alone is not enough, because more than one starter was fitted during production.

Does the starter need any maintenance?

No routine maintenance is required. Keeping the battery, terminals and earth connections clean is what extends starter life in practice.

Is a 12V and a 24V starter interchangeable?

No. The voltage rating must match the vehicle system; fitting the wrong unit will damage the starter and the wiring.