What are the causes of weak starter rotation?
4 Answers
The causes of weak starter rotation are: 1. Insufficient battery power or loose, poor contact of connecting wires; 2. Starter bearings being too tight or excessively loose; 3. Burned contacts in the starter switch or short-circuited electromagnetic switch coils; 4. Open or short circuits in the series auxiliary coils of a moving-armature starter. Symptoms of weak starter rotation include: 1. The starter rotates slowly and weakly, making it difficult to drive the engine; 2. When the starter switch is engaged, the starter only makes a clicking sound without starting. The starter, also known as the motor, converts the electrical energy from the battery into mechanical energy to drive the engine flywheel and initiate engine startup.
When my car starts, the starter turns very slowly and can't get going. Actually, this is quite a common issue. In most cases, it's due to insufficient battery power, especially after a few years of use—the battery ages, internal resistance increases, and output power drops in cold weather, leading to weak starting. Then there's the issue with the starting circuit; if the positive and negative terminals are oxidized, rusted, or the screws aren't tightened properly, the current can't flow smoothly, and the motor naturally won't turn fast. Additionally, if the starter's brushes are worn out or the internal copper sleeve is burnt and short-circuited, it can also reduce the rotation speed. Sometimes, it's the relay contacts being burnt out, preventing the signal from passing through. I recommend first testing the battery voltage—a fully charged battery should read 12.6V or higher; if it's low, charge or replace it. Check the terminal connections and clean them—don't force-start to avoid burning out the motor. Usually, turn off the AC and lights when parking to extend battery life. Using winter-grade oil in cold weather can reduce the starting load.
When the starter motor is turning weakly, I think the first step is to check the battery condition yourself. Open the hood and use a regular multimeter to measure the battery voltage—if it's below 12V, you'll need to charge or replace the battery. Next, inspect the positive and negative terminals, clean off any dust and rust, and ensure they're securely connected. Then check the starter relay, which is located in the fuse box—sometimes burnt contacts can weaken the control signal. The next step is to examine the wear on the starter motor's brushes; excessive wear can hinder current flow. Also, pay attention to any short circuits in the starting circuit, as damaged wiring can affect overall transmission. I often encounter issues in rainy or snowy weather when moisture degrades wiring performance. It's advisable to check the battery fluid level monthly and add distilled water if necessary. Avoid frequent short-distance starts and stops, as these drain the battery the most. Don’t delay addressing any issues, as they can easily lead to bigger failures.
The starter's lack of power to turn is usually due to a battery issue, such as insufficient charge, aging, or inability to hold a charge. It could also be caused by poor contact or oxidation in the starter wires, affecting current flow. Internal wear in the starter, like worn-out brushes, or burnt relay contacts leading to poor control, may be the culprit. Cold weather can significantly reduce battery performance. For inspection, it's recommended to first test the voltage and charge or replace the battery if necessary. Clean the terminal connections to ensure they're not loose. Avoid leaving lights on when parked to prevent deep discharge.
