This guide outlines some of the possible causes that you can use to troubleshoot auto-connect issues, and then presents some fixes that you can try to resolve.
Check grounding with an ohmmeter. If the ground is good, the fault is inside the component. If there is no voltage in the hot lead to the component, the problem is in the wiring. Go back through the fuse box (or relay, or circuit breaker) until you find voltage.
Electrical troubleshooting can be a tedious task, but it doesn’t have to be if you follow a few simple rules: every circuit needs a power source; Most electrical devices require a minimum voltage to function properly. and all chains require continuity. As a result, most electrical problems are caused by low voltage (or no voltage), excessive resistance, or loss of continuity.
Safety is always an important aspect when working with electrical systems in vehicles. Except for the high voltage side of the ignition and battery system and HV high voltage circuits, there is NO risk of electric shock. Twelve volts (12V DC) is not enough to make you feel. There is a risk of unintentional short circuiting in a hot circuit and damage to wiring, PCM or other on-board electronics, or fire.
ATTENTION! If your car is Is a HV battery hybrid, there is a risk of electric shock from direct contact with the HV battery, cables, or other HV components. For more information on this topic, see Hybrid Security Threats
WARNING: When performing electrical repairs or replacing electrical or electronic components, the battery should ALWAYS be disconnected to reduce the risk of accidental short circuiting. Disconnecting the battery causes most PCMs to forget their learned settings. This may cause driving problems or require special “retraining” with a scan tool. To avoid this type of hassle, use a 9V “splash” plugged into your car’s cigarette lighter to maintain battery voltage, or connect a 9V alkaline battery to the PCM – Power On.
For additional safety information, see Battery Safety.
ELECTRIC CIRCUIT TESTS
All circuits require voltage for the operation of components connected to this circuit. So if there is no tension, there is no function. Thus, the first task when troubleshooting electrical faults is to check for voltage at the load point in the circuit.
The load point is the element that the circuit must supply with energy, such as B. a light bulb, wiper motor, blower motor, idle stop magnet, etc. And all you need to quickly check is a 12 volt voltmeter or test lamp that comes on when the voltage is turned on. A voltmeter is the best tool for this because it will give you accurate readings, but the test light is good for making quick voltage checks.
Using a test light is a quick way to check voltage.However, a voltmeter is more accurate.
Suppose you cannot find the voltage at the load point. Yep, you found the first indication of the problem. Check the fuse, fuse or circuit breaker protecting the circuit or the power relay supplying the circuit.
If passedThe problem is a blown fuse, replacing the fuse may temporarily restore power. However, unless the root cause of the overload is found and corrected, your “fix” is unlikely to last long. Whatever you do, do not replace a larger fuse. A larger fuse can potentially handle a larger load, but not the wiring and the rest of the circuit. The circuit for a 20 amp fuse is rated for a maximum of 20 amps. Period.
A defective circuit breaker or open relay acts in the same way as a blown fuse. Circuit breakers are often used to protect circuits that may experience short-term overload phases, for example. B. with air conditioning compressor clutch.
The easiest way to test a circuit breaker is to disconnect it with a jumper. Your patch lead must have a replaceable built-in fuse to protect the circuit from damage. Use a fuse that does not exceed the rating of the circuit itself. If you don’t know, useUse a 5 or 10 amp fuse for your safety. If the circuit works when you bypass the circuit breaker, you have isolated the problem. Replace circuit breaker.
The relay in question can also be tested using the same basic test. A relay is nothing more than a remote switch that uses an electromagnet to close a series of contact points. When the relay magnet is energized, the points are closed and the battery voltage is passed through the main circuit. Relays are often used in circuits to reduce the amount of wiring required and reduce the current flowing through the main control switch. Thus, a switch, timer, or sensor with relatively low amperage (do it inexpensively) can be used to turn on and off relays with much higher wattage.
VOLTAGE TESTS FOR ELECTRICAL PROBLEMS IN A VEHICLE
Each electrical device requires a certain voltage to operate. The lamp glows with reduced brightness when the voltage drops. However, some components have a threshold voltage below which they do not work at all. The starter motor can start the engine more slowly at low voltage, but if the battery voltage is too low, it will not be able to start at all. The minimum threshold voltage is especially important for components such as solenoids (which require some tension to overcome the spring resistance), relays, timers, buzzers, horns, injectors (which are also solenoids). and most electronic devices (ignition module). Computer and radio).
If you test the charging point for full battery voltage, you can determine if the voltage is sufficient. You will need a voltmeter for this. The battery itself must be at least 70% charged and indicate 12.43 V or more (12.66 V fully charged). If the battery is discharged, it should be charged and checked. The charging system should also be checked and it should be about 1.5-2.0 V higher than the base voltage of the battery (about 14 to 14-1 / 2 V). If the battery is good, your willThe meter should indicate a voltage within 1 V of the battery voltage at the load point of the circuit in that circuit.
Low voltage in a circuit is usually caused by excessive resistance at any point in the wiring. This usually means a loose or corroded plug, a faulty switch or relay, or poor grounding. To find the point of high resistance, use a voltmeter to perform a “voltage drop test” at various points in the circuit. If the voltmeter shows a voltage drop of more than 0.4 V across the outlet, switch, or ground pin, it is a malfunction. Ideally, the voltage drop should not exceed 0.1 volts.
If more than one circuit is low, perform a voltage drop test at the battery terminals and at the engine / body ground straps. Loose or corroded battery cables and ground straps are a common cause of voltage problems. Clean and tighten battery cables and / or grounding tapes as necessary.
Sometimes too little wiring can lead to the bottomto whom stress. This is not something you find in many OE wiring circles, but it is a common mistake made when installing accessories in the aftermarket with your own hands. The higher the load current in the circuit, the higher the measured value required for wiring.
Sizes Of Cables And Loads In Amperes
The following list shows the recommended wire sizes for various amplifier loads:
NOTE. These values refer to copper wire at a maximum temperature of 60 ° C (140 ° F).
Capacity in amperes
ELECTRICAL CONTINUITY CHECK
Each circuit requires a complete circuit to work. The voltage across the load is useless if the battery is also not fully grounded. Bodenweg met everyone