How To Properly...
Diagnose a Car Problem
Well first off lets look at the different systems of the car. We have electrical, combustion, intake, exhaust, ignition, charging, cooling, air conditioning, steering, brakes, wheels and body.
If we have an electrical issue the first place to look if something does not work is the fuse panel. They are usually located under the steering wheel somewhere or in the engine compartment either on one of the sides or the back. take the cover off of the fuse box and there should be a list of what fuse controls what electrical item on the car. Find the one that does not work, say the radio and pull the fuse out. look at the fuse through the clear plastic and see if the little wire inside is still whole. If not then replace the fuse with the proper amperage fuse. If it's still good we move on to the item it's self. you can also purchase a fuse tester that you just touch the exposed metal contacts on the fuse and if the fuse is good a light will illuminate on the tester. If the fuse is OK then look at the item itself. If it's a light the most likely its the bulb. If it's a radio then some radios might have a separate fuse in the back or the power wire could have come loose. Disconnect the item that does not work and take a voltage meter and test the power wires for power. If there is power then it's the item itself that need replacing. If there is no power and the fuse is good then there is a problem in the wiring. that should be taken to a mechanic to fix.
If your car does not start then it's either the battery, ignition, timing, starter motor or spark plugs. If when you hear nothing when the key is turned then it will either be a dead battery or a blown starter. Jump the car, if that does not work then either the ignition is broken or the starter blew. If ignition works ok then you should be able to run at least the radio and electrics of the car. The starter will have problems if there is only a click sound, that means the gears are stuck or the electromagnets have blown. That's when you need to get a new starter.
To check your spark plugs take one out and hook it back into the wire and set it on the engine block. Try starting the car while you have someone look to see if there is a spark at the end of the plug. Do this with each plug. If here is a spark then the plugs are fine, if not replace them.
If the problem lies with your charging system then an alternator needs to be replaced. You can test this by running your car and looking at the voltage at the battery. If the alternator is working you should be able to test with a multimeter a voltage of more then 13 volts at the battery, if not alternator is broken.
If your car is over heating then look at the coolant level, if needed fill up and that should help. It might also be a water pump if your car has one of those. You can tell that's out when as soon as the car overheats you lift the hood and there is water everywhere ans steam.
Brakes are easy. take off the tire and look at the pad. If the pad is thin then it needs to be replaced. You can also check the brake fluid reservoir in the engine compartment. DOT3 brake fluid is most commonly used. if it's low then you should fill it. Low fluid usually accompanies "soft" brakes.
