The Automotive Electrical System
If your vehicle is showing signs of electrical system trouble, don’t delay. Bring us your vehicle so we can assess the situation, make sure all the system voltages are correct and prevent further (more expensive) damage. Electrical system failure will leave you stranded.
What is the Electrical System?
The automotive electrical system monitors and controls nearly every operational feature and component of your vehicle.
The electrical system directly powers:
- Windshield Wipers
- Power Door Locks
- Power Windows
- Head Lights, Tail Lights, Turn Signals
- Interior Lights
- Interior Controls (Radio, Heater, A/C, ...)
- Instrument Cluster (gauges and warning lights)
The electrical system also includes Sensors (to monitor) and Systems (to control):
- Throttle and Engine Speed
- Cruise Control
- Anti-Lock Brakes (ABS)
- Traction Control
- Fluid Levels
But wait there's more! The electrical system also starts your vehicle, which allows all those other systems to work.
Key components of the electrical system are:
- Starter Motor
- Alternator and Charging System
What the Battery Does
Until your vehicle starts, your battery provides 100% of its power.
That all starts to change when you turn the key. Your battery powers the fuel pump, ignition and starter motor, and the starter actually gets the engine moving.
It takes a lot of juice to do all that, so as soon as the engine is running the alternator starts re-charging the battery so it's fully powered the next time you need it.
How Long Does a Battery Last?
Most modern batteries can be expected to last 3 years, under normal vehicle operation.
However, if you mostly drive very short trips (less than 20 minutes), your battery does not get a chance to fully recharge. This driving scenario will shorten your battery life.
The harsh heat of Austin summers can also hasten your battery's demise. In our hot-weather climate, you can assume a new battery will last 2 years, but you should have it checked every year after that.
Signs of Battery Trouble
Any of the following symptoms could indicate a dead (or about to be dead) battery:
- Vehicle won't start
- Vehicle is slow to start (makes "ruh ruh ruh" sound)
- Headlights and interior lights dimmer than normal
- Accessories that don't work
- Check engine light (dashboard symbol) illuminated
- Battery dashboard symbol illuminated
- Battery is swollen or bloated
- Bad smell - sulfur or "rotten egg" smell around the battery could indicate a leak.
- Post corrosion - gunk near the (+) and (-) cable connections could indicate a leak.
- Age - the older a battery, the more likely it is to fail.
The Starter Motor
What the Starter Motor Does
The battery turns the starter motor on, but the starter is what really gets the engine going. The starter rotates the flywheel, which turns the crankshaft, which makes the engine’s pistons move.
Signs of Starter Motor Trouble
If your starter has completely failed, your vehicle won't start.
It can be difficult (if not impossible) for a driver to tell whether they've got a dead battery, a bad alternator, or a failed starter.
Our skilled technicians can recognize the warning signs of a failing starter, by checking to see if it's drawing the proper amount of current.
- Too much current means the starter is wearing out.
- Too little current might mean cables need to be replaced or connections need to be cleaned.
The Automotive Alternator
What the Alternator Does
Once the starter motor turns the crankshaft and makes the pistons start to move, the alternator kicks in. The alternator is like a little generator. It re-charges the battery and powers the electrical system while the vehicle is running.
Signs of Alternator Trouble
Your vehicle might start (turn over) with a faulty alternator, but it won’t run for very long. If the alternator is failing, the electrical system will start acting erratically - all of your lights might illuminate at once, for example. Shortly thereafter, your battery will lose ALL charge, and your engine will stop.
We can perform a complete electrical system check to see whether the alternator is generating the proper amount of current and voltage. Failed electrical test results indicate the alternator needs to be replaced.
A failed alternator WILL leave you stranded. It's best to replace an alternator before it completely fails.
What the Fuses Do
The alternator produces a lot of juice (amps), and some circuits only need a little. The fuses help protect the high amp-to-low amp conversion.
- Large-amp fuses protect high-amp circuits like the cooling fan and starter solenoid.
- Medium-amp fuses protect medium-amp circuits like power windows.
- Low-amp fuses protect low-amp circuits like the radio and interior lights.
Signs of Fuse Problems
If a fuse fails, current is not flowing on that fuse's circuit, so everything on that circuit fails. Some circuits have only one component, some have several. But when a fuse fails, one or more electrical things suddenly stop working.
Fuses are generally pretty reliable. But, like any electrical component, a fuse can suddenly simply fail. Replacing the burned out fuse will correct the immediate symptom(s), but it's important to check the circuit and electrical system to make sure the blown fuse isn't an early symptom of a more serious electrical problem.