HORN WON'T SHUT OFF on 2004 AVEO

[2010AveoLT]

Ok I went out today, put the under the hood fuse back and the horn is blaring. I removed the horn relay under the drivers side kick panel and the horn continues to blare. It is now obvious to me the horn switch in the steering wheel is not the problem. So where is the short? 2010AveoT says it may be in UBEC, What is UBEC and where do I look? Rocky 49

the UBEC is the Underhood Bussed Electical Center; or in other words, the Underhood Fuse Box.

[rocky49]

After hearing from others the issue must be in the underhood fuse box, I went to pick your part for some training. I found a broken up fuse box and took it apart. The one off a 2005 aveo looks quite a bit different from later models. It became obvious to me that I could not take this box apart on my car in any non destructive manner. So I went back to basics and decided to check for shorts in the wiring harness. Pick your part was again helpful because I could trace the harness back from the horn to junction box. No such luck as any easy spice. I played a bit with their shredded harness and decided to go home and work on mine some morel At home I found that I stopped tracing the horn circuit at the passenger headlight connection. I started peeling crinkle wrap off the harness and found that I had a melted section of wrap, peeled it off and found 3 wires with insulation burned off and bare wires. I peeled the crinkle plastic off for another 6 inches and looked for more bare wires touching. None found. I put the fuse in and the horn blasted. I then separated the wires from each other and the horn stopped. I applied shrink wrap to the three wires separately and then bundled them up with electrical tape. Checked all circuits and everything works properly. For those curious about where the overheated stretch of wires were, it was along the stretch on the lower rad support just past the connection the goes to an engine sensor. This stretch of wire is well supported so the failure was not due to fatigue but overheating. Speaking of heat today in frigid northern Canada it was 40 F degrees in the sun, so it was a good day to work on the Zombie and solve this final problem. Thanks to those who commented and helped with ideas along the way. ROCKY

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