Mechanics

ELECTRICAL SHORT

1998 BMW 323 • 6 cylinder 2WD Manual • 130,000 miles

EH41867 last 7 digits of the VIN.
hi, I got a problem I got a short in the electrial system somewhere. Its the right side front and back lights, by that I mean the front right yellow light but not the blinker(the blinker works) and the back right light(its not the brake light but the light thats stays on when you turn on the lights). I tried replacing the fuse with the correct one(10) but it would just burn or sometime they would stay on for a min. Or two. I replaced both front and back bulbs and I checked the connectors they are fine not dirty or broken. I took the harness out and looked at the wire that where visable and there where 2 wires touching each other that had insulation damage so I put electrical tape around each wire, but that still didnt work I figure there has to be another one. Am I going to have to trace the wire back to the fuse box or can I do something else? I got a multi-meter but no clue how I would use it to fix it.
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Mpetruescu
March 29, 2012.



The meter won't help. The ohm meter will tell you there's a short, ... While it's present, but you already know that.

A simple trick to finding a short is to replace the blown fuse with a pair of spade terminals, then use small jumper wires to connect them to a 12 volt light bulb. A brake light bulb works well. When the circuit is live and the short is present, the bulb will be full brightness and hot so be sure it's not laying on the carpet or against a plastic door panel. Now you can unplug electrical connectors and move things around to see what makes the short go away. When it does, the bulb will get dim or go out.

Caradiodoc
Mar 29, 2012.
By the way, once the shorts are all found, get rid of that electrical tape. In hot weather it will unravel into a gooey mess. The best is to seal the wires with heat-shrink tubing. They make it now with hot-melt glue inside to really seal out moisture. The only problem is you have to cut the wire to slide the tubing on, then splice and solder it. If you can find a connector nearby, remove the terminals one at a time, and slide the heat-shrink tubing on there and down to the area to be sealed.
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Caradiodoc
Mar 29, 2012.

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