How to Troubleshoot the Electrical System in Cars

by Contributing Writer; Updated June 12, 2017

The Ford car appeals to people who like what Ford car stands Ford car but who still want an economy car to combat rising gas prices. The Ford car fits the bill on many levels. Its electrical system runs about average, which means the longer you own one, the more electrical problems you're likely to see. Most of them are a quick fit.

Under The Hood:

 How to Troubleshoot the Electrical System in a Honda Accord

Pay attention to the alternator warning light, more commonly known as the idiot light. It can help you catch problems before they become a major hassle. Your idiot light should come on when your turn the key to your Accord on without starting the engine. If it doesn't come on, check for a blown fuse first. If that doesn't repair the light, check the wiring and bulb to the light circuit.

Explore whether weather conditions have anything to do with the charge indicator light going on. Extended idling on hot days can overheat the alternator, lowering its output and the ability of your electrical components to receive power. This is common and should resolve itself as the engine cools.

Check for poor connections at the battery or a problem relay if your Honda Accord is sluggish about starting. The starter is your car's biggest electrical component. Unless your car is several years old, the problem may exist in the connections, solenoid or key switch. The starter in an older Accord may just be worn out and need replacing.

Assess the condition of the connector in the charging circuit wiring harness. Some 1982 Accords were fitted with circuit wire that didn't have a large enough diameter to handle the current from the alternator. This can lead to a melted connector that causes repeated battery and alternator failures.

Look to see if the light in your Honda glove box stays on after you've turned off the engine. This problem, commonly seen on 1991 to1992 Accords, drains power from the battery. After checking for an aligned glove compartment, you might need to apply a retro-fit tube cap over the too short switch plunger to extend its length so that the light will shut off.

Verify the mileage on your 2003 Honda Accord if your dashboard LCD lights have gone dead. This was such a particularly frustrating problem for owners that Honda extended the warranty this problem to 100,000 miles or seven years. Contact American Honda or your dealer about getting it repaired under warranty.

Have your Accord's electrical system load tested on occasion to make certain it's fully operational. Testing circuit loads with ammeter and other tools will let you know if your Honda's electrical system operates at 80 to 100 percent capacity.

 How to Troubleshoot the Electrical System in a Cadillac Escalade

Replace an older battery with a recommended replacement if you're experiencing one electrical glitch after another. Be prepared to pay more because the cheapest batteries just don't have what it takes to power an Escalade.

Rule out battery or alternator problems first if you have a starting problem. If they test ok, you may have a problem starter. Use an ohmmeter to test the resistance reading of the solenoid. Replace the solenoid assembly with a high or low resistance reading. A reading over 1.3 ohms may mean a break in the winding continuity. If your reading is below 0.8 ohms, you probably have a short in the winding circuit.

Consider checking your headlamp wiring if lamps flicker or remain off. The cause could be an electrical overload. Overload can also cause problems with the windshield wipers too. However, if ice or snow exists, clear from the windshield first and then try your wipers.

Recognize that the wiring circuits of a Cadillac Escalade use a combination of circuit breakers, fuses and fusible thermal links to reduce the chance of fire. Access the panel fuse block on the driver's end of the dash or the underhood fuse/relay center near the brake fluid reservoir at the end of the engine compartment. If you notice a broken or melted silver band inside a fuse, remove the fuse with a fuse extractor and replace it with one with identical amperage.

Realize that electrical system troubleshooting sometimes lies in the codes in the controller. Start checking for stored trouble codes. If testing reveals a wiring problem, a wiring schematic can help you repair it. Clear any trouble codes so that they don't reset.

Check if the power liftgate refuses to unlock from your car remote or the overhead console switch. If you have this problem with a 2007 Escalade, you have a software problem that requires reprogramming the TIS Remote.

Get help from a certified mechanic if your SUV exhibits powertrain problems. The electronically-controlled transmission and electronic throttle control provides major horsepower that can only be serviced by a mechanic with the right knowledge and tools.

Items you will need

  • Fuse extractor

  • Screwdriver

  • Ohmmeter

 How to Troubleshoot the Electrical System in a Mazda 6

Enjoy the pretty light show that you get when the Mazda 6 doesn't start. If the flashing lights and spinning needles of your electrical system appear, your battery is most likely dead. Most Mazda batteries last approximately 3 to 5 years, but extreme weather conditions might shorten a battery's life.

Check your fuses if your radio suddenly goes out, even if the display still works. Chances are you've blown a fuse. Checking the fuse box for electrical system problems is often your first step in troubleshooting.

Try another key fob if your Mazda 6 power windows act out on their own, particularly if they go down after you turn off the car and try to lock the doors and set the alarm system. If the system doesn't work with the other key fob, ask your dealer about reprogramming your key fob. If the windows fail to operate correctly with either key fob, try the initial setting instructions in the next step.

Restore your power windows to the factory setting if they don't work after replacing your master window switch or battery. With your engine running, press the power window switch down until the window is down. Pull window switch up for one click, and then pull switch in for 2 seconds or more after the window closes until you hear a click or a beep.

 How to Troubleshoot the Electrical System in a Chrysler Sebring

Avoid many electrical problems by keeping battery posts and other connections clean and free from corrosion.

Check your key function if electrical components suddenly stop working. Sebring keys have an internal transponder. When it dies, so can parts of the electrical system. Try another key if you have one available. If the problem continues with any key, check the ignition switch.

Test the starter when the battery checks out but driveability remains an issue. Starter problems come from poor connections, the starter relay or problems with a switch (most likely transmission range, clutch interlock or ignition).

Take a closer look at your door latches if interior lights go on and off, even setting off car buzzers or alarms. A door that doesn't latch securely will set off all kinds of warnings. Get the latch repaired.

Investigate the cause of a broken tachometer (RPM gauge) first at the tachometer drive module on the circuit board. If the module works, the problem probably lies in the wiring.

Replace or repair the instrument cluster if all your electrical system problems lie in the instrument panel. With a properly working instrument cluster, the data bus can manage the data effectively, providing you with working instruments in your Sebring.

Perform or schedule an electrical system check whenever driveability is in question or around every 2 years in order to catch problems early. Measure circuit load with an ammeter and circuit voltage drops with a digital volt-ohmmeter (DVOM). Replace or repair the instrument cluster if all your electrical system problems lie in the instrument panel. A properly working instrument cluster allows the data bus to manage data effectively.

Items you will need

  • Ammeter

  • Digital volt-ohmmeter (DVOM)

 How to Troubleshoot the Electrical System in a Ford F-Series

Look to your alternator if starting your car provides you with a click instead of an engine roaring to life. However, even a truck that starts can have alternator problems. Check the headlights while the pickup is idling; if they get weaker, you may have a loose alternator belt or loose connections. Rust also affects the Ford alternators.

Have the Generic Electronic Module (GEM) tested or scanned for fault codes if your windshield wipers don't turn on. This will tell you where the problem lies. The GEM controls all electrical items.

Check whether you have electrical problems after your truck sits in the rain. If so, your windshield may be leaking onto the GEM, located behind the passenger fusebox.

Watch the gauges on your dash when you start your engine. If it takes the gauges awhile to wake up, they're not getting their dose of voltage from the battery. Get your battery checked.

Find out if multiple electrical problems are related by checking the battery first. Sometimes, if a cell drops in the battery of a Ford truck, the electrical system goes haywire. Otherwise, the problem might lie in the Body Control Module, a cluster or a pinched wiring harness.

See if wire conductors are the problem. Metal fatigue isn't a common problem in the Ford pickup, but sometimes a lot of off-road driving can affect the wire mounting points.

Use the Power Distribution Terminal (PDT) if you need to power up devices that create a large power demand. Located at the starter solenoid, the PDT is always "hot."

 How to Troubleshoot the Electrical System in a Honda CR-V

Beware of voltage variations that may affect your electrical system components or day-to-day driveability of your Honda. The variations can alter computerized controls.

Ask about a free service test the next time you pass one of the chain auto parts stores. This is a higher level of testing than voltmeter testing. You can also invest in an auto electrical technician if you want a more complete testing of your electrical system.

Find out if you have a Bosch REMAN starter SR0445X if you're experiencing problems with your starter. A one-way clutch installed for smoother starts actually hangs up the ignition lock cylinder assembly, which overheats the starter and drains the battery. If you have this problem, you must replace the entire lock cylinder, electrical switch unit and steering lock.

Keep battery, connections and battery cover vents clean. Corrosion that builds up on your battery can make life difficult for your starter. Clogged battery vents can lead to a build up dangerous gases. Fix any loose connections to for a quick fix to electrical problems.

Take your SUV in with all remotes if the security system doesn't work. A bug in the system causes the control unit to change modes. A certified repair person must replace the security control unit and microphone behind the lower dashboard cover on the driver side and reprogram your CR-V security remotes.

Contact Honda with your VIN number if you own a 2005 HONDA CR-V to see if your vehicle is one with a faulty passenger position detection system side sensor. If so, the air bag may deploy when a passenger is out of position, leading to injury. If your car falls in that category, your dealer should replace the passenger seat back pad that holds the position detection system sensor.

 How to Troubleshoot the Electrical System in a Ford Focus

Check the relay for the air conditioning if you're not getting any air through your vents. If it checks out and you have Freon, look at the low pressure switch on the air conditioning system. A bad lower pressure switch causes the compressor clutch to shut down.

Look in the resistor network of the blower module instead of the fuses when you get air on one setting, but not the others. Most likely, your Focus has a blown thermal fuse. If you're adept at auto repairs to the blower motor, you might be able to do this repair yourself.

Consider a water leak in the Climate Control Heater Blower Motor Case if you have a Ford Focus from 2000 to 2003. Models from those years occasionally have problems with leaks. The cowl area needs to be sealed.

Reset your car's computer if you've made a fix, but the warning light continues to come on. You'll need to remove the battery cable from the connector for at least 30 seconds to reset the computer. The Ford Focus sometimes gives off faulty warnings that can lead to costly trips to the mechanic to find out why a warning light is on.

Listen for a click when you try to start your Ford Focus and fail. It's a sound car owners dread hearing because it often means an alternator needs replacing, often a costly repair. First, check that connections are clean, tight and rust free. Also, a loose alternator belt won't charge.

 How to Troubleshoot the Electrical System in a Kia Spectra

Replace your battery when necessary, but make certain you match it to the same wattage of your existing battery. The Kia is configured for a specific wattage; if you go over or under that, you might cause all kinds of problems with your electrical system.

Track down widespread component power loss. If the battery and alternator check out, there may be a problem with the power module or computer.

Try first to replace the battery in your transmitter if the buttons for opening the door or the panic button or trunk button don't work. If a fresh battery doesn't do the trick, try to check the charge in the key transmitter with a digital volt ohm meter (DVOM). If everything checks, your transmitter may need reprogramming.

Hook your car up to get the problem code when you have an electrical problem that has you scratching your head and wondering where to start. Problem codes give you the heads up. In particular, problem codes can direct you to various sensor malfunctions, whether it's the oxygen sensor or other sensors. The Kia Spectra seems to have a sensor for everything.

Carry around the different size fuses that your Spectra requires. You never know when a fuse will blow. If you have fuses available, it's a quick fix and you're back on the road in no time.

Items you will need

  • Digital volt ohm meter (DVOM)

 How to Troubleshoot the Electrical System in a Ford Taurus

Give your Ford Taurus the once over if you haven't driven it for awhile. To get it up and running, you need tight, clean battery connections. Check for and replace any blown out fuses as well. Auto parts stores often test the charge your alternator is putting out for free.

Watch out for rust on the alternator. Alternators on the Ford Taurus can't get a proper charge to power the rest of the car if rust develops. Headlights might get weak or your car may not even start because the alternator can't get power to the battery.

Replace the alternator with a rebuilt one if your car won't start despite all your efforts. Rebuilt alternators often work just as well for much less.

See if your 2006 Taurus meets the qualifications for a recall repair with an airbag warning light that stays lit. This model came with a special overlay wiring harness to allow for hands free cell phone usage. Unfortunately, circuits for the air bag light were omitted. For safety reasons, this is an electrical repair that needs to be made.

Get your windshield wipers to the down position when you turn them off by trouble shooting the wiper motor gear case. If you're knowledgeable about electrical systems, go ahead and repair the park switch or just change out the entire wiper motor assembly to limit the possibility of future problems with your windshield wipers.

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