2002 Ford Focus Q&A
2002 Ford Focus Question: Can check battery light be caused by a clogged fuel filter or failing fuel pump?
Car has received a new alternator and battery within the last 4 months. The check engine light came on as well as the check battery like, but after cleaning the IAC valve, the check engine light went off. However, the battery light continued to come on intermittently; could this be caused by the fuel pump? Currently, the car cranks but does not start, and will not take a jump. - LMCc
no. it is a charging system issue. the check engine light could be anyone of over 1500 codes. Roy - mastertech6371
Check the fuses and fuse links in case one of these is blown.If the battery light was coming on the alternator was not charging properly. Turn on the ignition switch to the on but not run position. Do you see an icon on the instrument panel representing a battery, if you do not see this battery icon the alternator was not seeing power to allow it to charge. After you do get the engine started, run the engine does the battery icon go out. Put a volt meter across the battery terminals with the engine off, at rest the battery voltage should be 12.6 volts if the battery is fully charged. Now get a friend to start the car while you watch the voltmeter, the voltage reading across the battery should read approximately 14.6 volts if the alternator is charging correctly. It's best also to properly test the alternator by using an oscilloscope to look at the alternator diode patter. To address the no start condition ,see if you have fuel and spark going to the engine.Check for fuel pressure (you will need a fuel pressure gauge and look up the specified fuel pressure for your vehicle). Remove the fuel hose that goes to the fuel rail and get a friend to crank over the engine to see you have adequate fuel volume (you should have approximately 1 pint of gasoline in ten seconds of cranking). Off course take proper precautions as gasoline is highly flamable. Next "listen" to the fuel injector. Using a mechanic's stethoscope (or use a long screw driver placing the handle end up to your ear place the metal tip end of the screwdriver against the body of the fuel injector), get a friend to crank over the engine while you "listen" to the fuel injector listen to each injector at the same point of the injector body. You should hear "click, click, click" as the injector is electrically opened and closed by the computer. If the injector is not being triggered you will not have fuel getting into the engine's cylinders. Disconnect the electrical connector at the fuel injector with the ignition key in the "on" position, (next position after the accessory position) you should have 12 volts at one of the two wires at the injector. This true for most vehicles but you need to consult a workshop manual for your vehicle to see that this is true for your vehicle. When the engine is running the second wire at the injector gets (triggered) grounded by the computer in your vehicle many times a second controlling exactly when and how much fuel gets injected into the engine. To check for spark you need to check for spark at the spark plug/end of the ignition coil but this is over 20,000 volts and you stand the risk of shock if you don't know what your doing. There is a company that independent auto repair shops get their information from, this same information is available inexpensively for people that work on their own cars.. The information is year make and model specific, covering repair procedures, torque specifications, fluid capacities and specifications, service bulletins, component locations, wiring diagrams ect.... Alldata is very easy to navigate http://bit.ly/AllData_Repair_Manuals_Online - patrick mannion