About a month or so ago I was driving along in my car, and suddenly the radio, speakers, and I would soon find, the entire interior lighting, popped. I figured maybe it was just a fuse, wasn’t too worried about it. I popped the hood and found the engine bay fuse box, the ROOM fuse was popped (15a fuse). I found another 15a, and as soon as the pins made contact to the connector in the fuse box, the fuse popped instantly. So after a little research online I have a “dead short” or “direct short”, which I guess basically means that a hot wire is making contact to ground or neutral?? (Sorry if those are the incorrect terms, I have very little knowledge in electrical stuff.) But how would one go about fixing that? would I check all the components that are connected to that fuse in the interior, and unplug them one by one and try to replace the fuse each time to see which one might be faulty? I have tried spraying the fuse box with compressed air for electronics, and nothing.
Any help or advice on this would be greatly appreciated. thank you.
EDIT: First thing I did was remove the radio, and I heard some sort of rattling inside of it. I completely disconnected it, and tried a new fuse, just in case. Everything worked after I unplugged the radio. After that, I took apart the radio and found that there was a QUARTER inside of the components, which was causing the short. I took out the quarter, reinstalled the radio, and everything is back to normal. What are the odds? Thank you all for your time!
Trial and error is one way, disconnect the power to items or bulbs one by one and see which circuit is the troublemaker. One might go for probable issues, broken shorted wires in the harness that is in between the driver door and frame, or tailgate if so equipped.
Yeah or look for melted wires where they may have come in contact with the exhaust or hot engine. Unless you’ve got a whole bunch of spare fuses, I’d take a hard look first for the obvious. A wiring schematic would tell you what items were on that circuit and a factory service manual would show the routing of the wire harness so you’d see the likely possibilities.
Your comment about a direct short to ground or ‘return’ side of the circuit is absolutely correct. The term “Neutral” is really only used in the AC world rather than the DC or ‘direct current’ world.
To look for the problem I would first start with any wiring that has been added or modified. Disconnect those things first. Instead of using fuses to see if the short has cleared you can replace the fuse with a brake light bulb. You will need a bulb socket or add some wires to a bulb to connect the bulb to the fuse holder contacts. The resistance of the bulb will limit the current available to the short to safe level. When the short finally is disconnected from the circuit the brake light will either dim or go out. This is because the resistance to ground has gone up and the current can only get to ground through another light or load on that circuit. The direct path to ground has been removed by disconnecting whatever is causing the problem.
You obviously have a great mind @Cougar. Or you’ve been spying on me chasing down a short. I have some costly 12v test equipment but the most basic and often rigged up tools are the fastest and simplest. But among the ‘professional’ tools a basic compass and heavy duty flasher can track a short inside a large harness to its source. The kit with those pieces is so old I can’t recall where it came from and it just improves on the logical effort geniuses like us developed on our own.
A memorable effort at chasing down an intermittent ROOM fuse failure turned up a bare wire under the head liner that powered the vanity mirror in the passenger sun visor. Good luck with your problem and be thankful it’s not intermittent.
Thanks for the comment but I don’t think I can claim to have a great mind @Red_Knox. Though I do understand Ohm’s Law pretty well. I fully agree with your comment about having basic tools to work with, which can be very helpful in finding troubles. Some time ago I purchased a short finder kit like you described, that uses a compass to follow the current flow in the wire. I haven’t had the need to use it yet so it is still in the box, somewhere around here. Your comment about the short being in the headliner is very good. Anywhere power is always applied to is a potential area of suspect. Particularly to the ROOM lights. A pinched wire that has finally worn through the insulation is a very big possibility with this kind of trouble.
First thing I did was remove the radio, and I heard some sort of rattling inside of it. I completely disconnected it, and tried a new fuse, just in case. Everything worked after I unplugged the radio. After that, I took apart the radio and found that there was a QUARTER inside of the components, which was causing the short. I took out the quarter, reinstalled the radio, and everything is back to normal. What are the odds? Thank you all for your time!
