Automotive problems are always a headache.  Electrical issues or needing electrical repairs can be even more problematic.  The Columbia SC Auto Repair Pro is here to explain how to troubleshoot some electrical problems using a test light.  Using a test light is pretty simple and can often rule out certain problems in less time than using a Digital Multimeter or DMM.

The test light type of circuit tested can easily help you determine if you have voltage in a positive circuit.  Let’s say, for example, that the headlights are not coming on.  Of course, checking the fuse would be your first step.  If you know that your fuse is good, a circuit tester can be used to trace the electrical wiring path to see where the problem is. Remember, you should always check or test the easiest options first.  Getting into automotive electrical repairs can get hairy if you do not know what you are doing.  Be sure that you follow directions exactly and if you feel uncomfortable with any auto repair, electrical or otherwise, never proceed with the repair.  Take your vehicle to a trusted auto repair shop or mechanic that can perform the necessary auto repair in a safe manner with the proper knowledge to complete the repair without causing further damages.

Utilizing a test light electrical circuit tester can also aid in checking a ground circuit, but we will get to that part in a minute.  Before you begin, I want to make sure that you know the leads to your test light are reversible.  This means it will not matter which side you attach to the power source or the ground.  Do not have concern that you must use one end over the other in any given situation.

Mechanic Tip: Always test out your test light BEFORE starting to troubleshoot for automotive electrical repairs.  This is s simple test – just ground one end and use the battery to check it.

Using a Test Light to Test for Voltage

Let us look at the basics first.  You have a positive power source, like your car battery, and you have a ground.  The ground can be any metal that is exposed and bolted to your chassis.  Your test light will be between them.  If both ends have been properly attached to both the power source and the ground, the light should come on.

When you want to see if a wire has a positive voltage, first attach one end of the test light to a good, solid ground connection.  You will now touch the other end to the wire that you are testing.  If the light comes on, you have a good circuit.  It really is just that simple.

Using your Test Light for Testing a Ground Circuit

In the case that you know that a particular electrical component is getting power on the positive side, you can check to see that it has a good ground.  Considering that you already know you have a good positive connection, attach one end to the positive.  Next you will touch the other end of your tester to the ground wire for this specific component.  If you light up, you’re in good shape.  If not, you need to clean the contact points and check the ground wire’s path.  Once you determine where the issue is, ground connections are pretty easy to re-establish.

While automotive electrical repairs can be a real pain, this tutorial on how to use a test light just might be able to help you find your problem.  If you are still having problems or need a good, reputable mechanic, come by our auto repair shop in Columbia, SCSanford’s Automotive Service is a full-service auto repair shop that handles all types of automotive electrical repairs and all types of  domestic and foreign auto repair.