QuestionAlright, so whenever i turn my car on, my deck turns on and starts playing... but no sound. And i realized a few days ago whenever i hit a bump, rut, etc in the road, it starts playing. would this be a ground problem?, speaker wire shorting out on the frame? it's puzzled me for awhile now.
AnswerHi Andrew,
While it might be an internal short in the deck, the most likely answer is a short on one of your speaker wires. Most head units will shut down their internal amps if one of the speaker outputs gets connected to chassis ground.
Luckily, your problem is fairly easy to troubleshoot because most of the time, you're not getting any sound. (It would be much more difficult to find the problem if you had sound most of the time and just lost the output for short intervals).
The easiest way to track down the issue is to remove the head unit and disconnect it. Look for any uninsulated or damaged wiring in the head unit harness. Then use a digital multimeter to check for continuity with chassis ground on all the speaker wires. Set the meter for the continuity function (or DC resistance) and attach the black probe to a good ground point. The outside ring of the cigarette lighter works, or structural metal in the dash cavity. Then, touch the red probe to each of the speaker wires. If you find one that shows continuity with chassis ground, that's the likely source of the problem.
In most cases, if you have a shorted speaker wire, it's either behind the head unit or at the speaker location. Sometimes you can get a shorted terminal on the speaker itself. If you can't find any damage to the wires, disconnect the speaker and test each of the speaker terminals for continuity with the speaker basket. There should be no connection between the basket of the speaker and the wire terminals.
If you aren't able to find and repair the damaged wiring, then you may have to run a new wire from the head unit location directly to the speaker.
Hope this helps!
Brian
