Electrical problems are one of every car owner’s worst nightmares. As automobiles become more complicated and technologically advanced, electronics and electrical problems are becoming more common. And when you consider that a simple short circuit can immobilize a brand-new vehicle and cause as much damage as totaling it in an accident, car owners should be concerned. Below, we have detailed 7 things you need to know if you have electrical faults in your vehicle.
#1: Check the Title/Origin
There are dishonest car dealers who will repackage flood-damaged vehicles and sell them as new cars. Flood-damaged vehicles may look as good as any new car once they dry out. However, they often suffer from extensive electrical problems that can be tedious and expensive to solve. You should always verify the origin and title status of your vehicle before you go any further in trying to solve the problems.
#2: Check for Parasitic Drains
If you suspect that you have an electrical problem in your vehicle, you can check the electrical system for parasitic drains. In order to perform this test, you will need a multimeter and some hand tools to remove the negative lead on your battery terminal. By connecting the negative terminal in series with the multimeter, you can determine the amperage load that is being placed on the car battery when it is off.
If the amperage is reading higher than an acceptable range of 25 to 50 milliamps, then you can bet your money that you have a short somewhere or a device that is drawing too much power. When an electrical component develops an internal short or a wire’s insulation frays off and rubs against the body panels, this generates heat and creates a potential fire hazard. In most cases, however, there is no noticeable effect other than weak batteries from the parasitic drain.
In order to pinpoint the origin of the parasitic drain, you will have to start pulling fuses and relays, one at a time, while the multimeter is connected. If the amperage drops back down to a normal range, you have an idea of where the fault may be.
#3: Check the Factory Wiring Diagrams
Consult the factory repair manual wiring diagrams to figure out what is connected to a circuit. In many cases, wiring problems occur when an aftermarket radio is installed, in the engine bay, or along wires that run to your taillights or trunk. You may be in need of a Gold Coast Mechanic if the problem is beyond your range of expertise.
#4: Check Your Battery
If you are having electrical problems, it may be the battery itself that is causing problems. When the car is off, the battery should read over 12 volts on the DC setting of your multimeter. If the battery itself appears to be holding a charge and has no signs of corrosion or sulfur leakage, you may want to check the terminal clamps and leads for any signs of damage or loose connections.
#5: Check Your Alternator
In order for your electrical accessories to function properly, the alternator has to keep recharging the battery. You can test your alternator by probing the terminals of your battery when the car is running. When you first start the vehicle, the voltage should be over 12v and around 12.8 in most vehicles. Once you hit the accelerator and rev the engine above 3000 RPMs, the multimeter should jump to 13+ volts. The number will keep fluctuating as the alternator recharges the battery. A bad battery or short can kill an alternator and vice versa.
#6: Check Your Fuses
One of the easiest things you can do is probe the top metal slots of your fuses. Set your multimeter on its Ohms setting to measure resistance. If a fuse has infinite resistance and does not register a proper rating, check that fuse and replace it with a new one.
#7: Check the Condition of Wiring Insulation
On some of the older Mercedes-Benz vehicles, they used cornstarch to insulate the wires. This biodegradable material worked too well and led to a lot of premature deterioration of wiring insulation. Look for any worn insulation or wires melted together that may indicate short circuits and damage.
