I recently bought an old 2002 Hyundai Elantra, and it runs ok, except it won't start nearly every morning. My mechanic told me the battery's most likely going. The only reason I'm thinking it's something else is because every morning when I go to start the car, there's a loud, intermittent noise coming from the fuse box; it's like a loud grinding/electrical noise that only lasts about a second at a time, but continually comes back almost on perfect rhythm (think of your directional, same sort of rhythm). Sometimes the lights will flash on and off with the noise too. Could this be something other than a bad battery? Or is it possible that these symptoms suggest a more electrical problem? Any help is greatly appreciated!
From your description, I understand that indeed there is an electrical problem. I would start with what is called wiggle test. While engine is running, try gently to wiggle the fuse box back and forward. Should you find any abnormalities in engine running or engine stalls or anything that shouldn't be doing out of the ordinary, you can say that the fuse box is your problem. If all good, secondly I would remove the fuse box and do a pin test on all fuse box connectors from under the box (wiring harness that plugs into fuse box). This will tell you if any male connector is loose. Should you have any loose connectors, just close them up a tiny bid so that they wont move. Before you put the box back, apply some electrical stabilant to ensure proper conductivity on all electrical components. This procedure could be time consuming but is well worth it to try. Finally, before you do all these actions please, have someone doing an AVR test to ensure your battery is good and entire charging/starting system is normal. Hope this will help you.
