As a car owner, you probably know to change the oil or check the tires regularly—but when it comes to your vehicle’s electrical components, small oversights can turn into costly repairs. Today, we’re bringing in senior engineers from BDELI (a trusted name in auto parts like alternators, starters, and power window regulators) to break down 4 common maintenance mistakes you might be making. No jargon, just simple, actionable tips to keep your car’s electrical system running smoothly.
Mistake 1: Ignoring Alternator Belt Tension—It’s Not Just “A Belt”
Your alternator is the heart of your car’s electrical system, keeping the battery charged and powering everything from the lights to the radio. And the alternator belt? It’s the bridge that connects the alternator to the engine. But here’s the thing: most drivers never check its tension—and that’s a big mistake.
What Happens When You Skip This?
If the belt is too loose, it slips on the alternator pulley. This means the alternator can’t spin fast enough to charge the battery, leading to dim lights, slow window movement, or even a dead battery. Worse, the slipping belt wears down the pulley’s surface and the belt itself—eventually causing the belt to snap. If it’s too tight, it puts extra pressure on the alternator’s bearings, making them wear out early. A failing bearing will make a high-pitched squealing or grinding noise under the hood.
How to Check It (5 Seconds!)
Turn off the engine. Find the alternator belt (it’s usually a black rubber belt connecting the alternator to the crankshaft pulley). Press down on the middle of the belt with your thumb—you should feel a small amount of give, about ½ inch (1.27 cm). If it’s rock-hard or sags more than that, it needs adjustment.
Quick Fix
If it’s loose, check your car’s owner’s manual for the correct tension specs—you can adjust it using the alternator’s adjustment bolt (ask a mechanic for help if you’re unsure). If the belt is cracked, glazed, or frayed, replace it right away. A new belt is cheap compared to a $500+ alternator repair!
Mistake 2: Letting Dirt Build Up in Power Window Tracks—Your Regulator Hates It
Ever noticed your power windows moving slower than usual, or making a crunchy sound when you roll them up? Chances are, dirt, leaves, or even small pebbles are clogging the window tracks. And while it might seem like a “minor mess,” it’s brutal on your power window regulator (the part that moves the window up and down).
What Happens When You Skip This?
The window regulator uses a motor and cables (or a rack-and-pinion system) to lift the window. When dirt builds up in the track, the regulator has to work twice as hard to push through the grime. Over time, this extra strain wears out the motor’s gears and stretches the cables. Eventually, the regulator might get stuck—leaving your window halfway down on a rainy day, or not working at all.
How to Check It
Roll the window all the way down. Look into the track (the slot along the top of the door frame where the window slides). If you see dust, lint, or small debris, it’s time to clean.
Quick Fix
Grab a few cotton swabs and a bottle of rubbing alcohol (or a mild soap and water solution). Gently wipe along the inside of the track to remove dirt—don’t use sharp tools, as they can scratch the plastic. Once it’s clean, spray a small amount of silicone lubricant (not WD-40!) into the track. This reduces friction and keeps the window moving smoothly. Do this every 3 months, and your regulator will last years longer.
Mistake 3: Cranking the Starter Too Long—You’re Killing Its Lifespan
We’ve all been there: you turn the key (or press the start button), and the engine just clicks, or sputters but doesn’t start. It’s tempting to hold the key down for 10+ seconds, hoping it’ll “catch”—but that’s one of the worst things you can do to your starter motor.
What Happens When You Skip This?
The starter motor uses a small, powerful engine to turn your car’s main engine over. When you crank it for too long (more than 5 seconds at a time), the motor overheats. The windings inside the starter can burn out, and the solenoid (the part that connects the starter to the battery) can fail. Even if the engine finally starts, you’re shortening the starter’s life—what should last 100,000+ miles might die at 50,000.
How to Check It
If your engine doesn’t start on the first crank:
• Stop cranking immediately (release the key/button).
• Wait 30 seconds to let the starter cool down.
• Try again for 3-5 seconds. If it still doesn’t start, check the battery (are the terminals clean? Is the battery charged?) or fuel level before cranking again.
Quick Fix
If the starter is making a clicking noise but not turning, it might be a dead battery (jumpstart it first). If it grinds or whines, the starter’s gear (which meshes with the engine’s flywheel) is worn—get it checked by a mechanic ASAP. The longer you wait, the more likely the starter will fail completely, leaving you stranded.
Mistake 4: Forgetting to Clean Battery Terminals—Corrosion Kills Power
Your car’s battery is the source of all electrical power—but if the terminals (the metal posts on top of the battery) are covered in white or green corrosion, that power can’t flow. Most drivers only notice this when their car won’t start—but by then, the corrosion might have already damaged the battery or the alternator.
What Happens When You Skip This?
Corrosion is a byproduct of battery acid reacting with air. It forms a thick, crusty layer on the terminals, blocking the electrical connection between the battery and the rest of the car. This means the alternator can’t charge the battery properly, and the battery can’t send power to the starter or other components. Over time, the corrosion can eat away at the terminals, making them loose or even breaking them.
How to Check It
Open your hood (make sure the engine is off!) and look at the battery terminals. If you see white, green, or blue gunk on the posts or the cables connected to them—you have corrosion.
Quick Fix
You’ll need baking soda, water, a wire brush, and gloves (battery acid is corrosive!).
1. Mix 2 tablespoons of baking soda with 1 cup of water to make a paste.
2. Disconnect the negative cable first (the one with the “-” sign), then the positive cable (“+”).
3. Apply the paste to the terminals with a brush, and scrub gently to remove corrosion.
4. Wipe the terminals clean with a damp cloth, then dry them.
5. Reconnect the positive cable first, then the negative.
Do this every 6 months, and your battery will last longer—and you’ll avoid unexpected dead batteries.
Good Maintenance Starts with Good Parts
At BDELI, we’ve been designing auto electrical parts (alternators, starters, power window regulators) for decades—and we know one thing: the best parts are the ones that are easy to maintain and built to resist wear.
Our alternators use high-quality bearings that handle slight belt tension variations, so you don’t have to worry about perfect adjustments every time. Our power window regulators have sealed cables to keep dirt out, and our starters are built with heat-resistant windings to handle occasional long cranks (though we still don’t recommend it!).
But even the best parts need a little love. By avoiding these 4 common mistakes, you’ll keep your car’s electrical system running strong—and save money on repairs down the line.
Got a question about your alternator, starter, or power windows? Drop a comment below—our engineers are here to help!
Drive safe,
The BDELI Team