What are the reasons for the BMW 730 starter motor not responding?
3 Answers
BMW 7 Series failing to start can be attributed to the following reasons: 1. Lack of antifreeze: Some car owners use water or inferior antifreeze, which can cause the entire cooling system to freeze in extremely cold winter conditions, leading to engine block cracks. This results in the car's water pump being unable to function, preventing the engine from starting and potentially damaging other engine components. 2. Steering wheel in locked position: If the steering wheel is not straightened when parking and is turned beyond a 30-degree angle, it will automatically lock, acting as an anti-theft device that prevents the car from starting. To resolve this, straighten the steering wheel to release the lock while turning the ignition key. 3. Excessive carbon buildup in the vehicle: Regularly driving at high speeds can help reduce carbon deposits.
I've been driving for over twenty years, and it's quite common for a BMW 730 to have no response when starting. Most likely, the battery is dead. Cold weather or long periods of inactivity can cause the battery to age quickly, and the voltage may drop too low to start the car. First, try checking if the dashboard lights up. If the lights are dim or unresponsive, it's probably a battery issue. Another possibility is a stuck or burnt-out starter motor—if the starter fails, it won't turn and may make a clicking sound. Poor electrical connections, such as loose or corroded battery terminals, can also prevent current from flowing. Other causes include an activated anti-theft lock (if the key battery is dead, the system may lock and prevent starting) or a blown fuse, especially the starter fuse, which breaks the circuit. When this happens, avoid repeatedly pressing the start button, as it can damage more components. Instead, use a multimeter to check the battery voltage or try a jump-start. If that doesn’t work, tow it to a repair shop. Regular battery maintenance every few months can help prevent such issues.
As someone who frequently repairs cars, when I see a BMW 730 not responding at startup, it's usually an issue with the starting system. If there's no sound at all during startup, it's likely a fault with the starter motor itself—either the motor gear is stuck or the carbon brushes are worn out, causing failure as soon as power is applied. Alternatively, it could be an electrical circuit problem, where the battery voltage is normal but there's a short circuit in the wiring, such as burnt contacts in the starter relay, preventing the control signal from reaching the motor. Another possibility is interference from the anti-theft system; BMW's electronic anti-theft system is highly sensitive, and a weak key signal or a malfunctioning module can cause the system to refuse to respond—try replacing the battery. Additionally, the starter-related fuse in the fuse box might have blown, which can be easily checked with a simple inspection. A drained battery is also common, especially after frequent short trips where the battery doesn't get fully charged. It's recommended to first test the battery and starting circuit, and avoid forcing the startup. During regular maintenance, clean the connection points often and keep them dry.
