Having electrical issues with your car can be frustrating and expensive to fix. However, with some basic knowledge and DIY spirit, you can troubleshoot and resolve many electrical problems yourself without breaking the bank.
Understanding Common Electrical Issues
The electrical system in cars has gotten increasingly complex over the years. However, some common problems have simple fixes:
A dead battery is the most common electrical issue for cars. Possible causes include:
- Dying alternator not recharging the battery
- Parasitic drain from accessories running when the car is off
- Corroded or loose battery connections
- Old battery at the end of its lifespan
To diagnose, use a multimeter to check the battery and alternator voltage. To fix, recharge or replace the battery, tighten connections, and test the alternator.
Blown fuses interrupt the circuit and cut power. They act as a safety to protect car wiring from current overloads.
Signs of a blown fuse include:
- Electrical components not working
- Fuse looking burnt or broken
To fix, locate the fuse box and replace the bad fuse with a new one of the same amperage. Address any underlying issue that caused the fuse to blow.
The alternator charges the battery while driving. If it fails, the battery won’t recharge and will eventually die.
- Battery not charging properly
- Dimming headlights at idle
- Battery warning light coming on
To test, check alternator output voltage. To fix, replace the alternator if it's worn out.
Corrosion in electrical wiring builds up resistance causing components to malfunction.
Common signs are:
- Intermittent electrical failures
- High resistance when testing wires
- Green corrosion on wiring
To fix, clean corroded spots on wires, apply dielectric grease, and replace damaged wires.
Testing Electrical Components
Diagnosing electrical issues often involves testing components like fuses, wires, and modules. Basic tools include:
- Multimeter - Measures voltage, resistance, and amperage
- Test light - Illuminates when current passes through a circuit
- Jumper wires - Temporarily bridges connections to test circuits
Here are some tips for DIY testing:
- Start simple before complex diagnostics - Check fuses, wires, and connections first
- Consult a wiring diagram - Follow the circuit path to pinpoint failures
- Reproduce the symptoms - Getting a component to act up helps identify it
- Take safety precautions against shocks and shorts
Knowing how to use diagnostic tools helps narrow down the source of electrical gremlins.
Common Do-It-Yourself Fixes
With basic mechanics skills and tools, there are many electrical repairs you can successfully do at home:
1. Battery Replacement
A weak battery is the most common cause of starting troubles. Replacing it involves:
- Disconnecting the negative then positive battery cables
- Unbolting the battery clamp and removing old battery
- Putting in new battery and reconnecting cables
- Cleaning any corrosion on terminals
Just be sure to dispose of the old battery properly.
2. Alternator Swap
A faulty alternator must be replaced. To change the alternator:
- Disconnect the negative battery cable
- Remove wires connected to the back of the alternator
- Take out the mounting bolts and pull out bad alternator
- Install new unit and reconnect wiring
- Verify charging system operation
Having spare fuses, wires, and alternator parts on hand helps for a quick fix.
3. Fuse Replacement
To change a blown fuse:
- Locate the fuse box and pull out the bad fuse
- Check the fuse type from the rating printed on it
- Insert a new fuse of the same amperage into the empty slot
Always keep spare fuses in the glove compartment to easily restore electrical power.
4. Headlight Restoration
Foggy, yellowed headlights greatly reduce nighttime visibility. DIY ways to restore clarity include:
- Wet sanding with progressive grit sandpaper
- Using a headlight restoration kit with polishing compound
- Applying clear plastic sealant to protect the lens
Aiming the headlights properly again is also critical for safety.
Knowing Your Limits
While many electrical repairs are reasonably easy for DIYers, more complex issues should still be left to professional auto electricians. Cases when you may want to have a mechanic diagnose and fix the problem involve:
- Advanced computer or module failures
- Extensive wiring damage from rodents or accidents
- Electrical gremlins that Evade diagnosis
- High voltage hybrid or EV systems
Be realistic and strategic about repairs to avoid safety risks or getting in over your head. Even pros sometimes have difficulty tracking down elusive electrical bugs.
Maintaining your car’s electrical system does not have to drain your wallet if you understand common issues and take advantage of DIY repair options when feasible. Knowing how to judiciously troubleshoot problems using diagnostic tools is invaluable. Combining repairs you can comfortably handle yourself with leaving tricky ones to experts is the savvy, cost-effective approach to your car’s electrical needs.