Why is my car randomly refusing to start after new stereo install?

November 12, 2010 9:24 PM

Why is my car randomly not starting? I just installed a new stereo head unit and I assume it has something to do with the ground...

I wanted to save some money rather than letting Best Buy install my new head unit. It's nothing spectacular. Just a budget Sony unit replacing a factory unit in my Scion XA. I had the most trouble with the ground cables. There was one coming from the receiver and one from the harness that I wound together and then stuck to a screw somewhere on the inside.. The screw was screwed into a half plastic half metal surface if that makes a difference..


Well the car started 10 times today perfectly. But then I just went out to turn it on and nothing. Dead . No lights or anything. All I had to do to get it working again was disconnect the negative side of my battery for one second and throw it back on. Then started up just fine.

I assume this is going to be basic electricity stuff.

How can I stop my car from doing this? It's pretty frustrating.

posted by lakerk to Technology (4 answers total)

Is it still doing the same thing consistently, or since you did that does it fire up fine again? Sounds like your battery terminals just got a little corroded and needed to be agitated a bit.
posted by Esefa at 10:37 PM on November 12, 2010

Response by poster: It's happened twice now. I haven't tried it again this evening. But the first time it did it was right after I installed the radio. then drove it 5-6 times turing it on and off and then left it for 5 hours. Then it happened again.
posted by lakerk at 10:45 PM on November 12, 2010

I'd check all the grounds in the engine bay, starting with the negative terminal on the battery. Since the posts are soft they might be worn down some and you'll have to tighten the terminal as tight as you can. Some dielectric grease on the terminals and the grounds will help with conductivity, and it will protect things from getting corroded any further. I have had similar problems in GM vehicles, some of the chassis grounds were corroded, so I cleaned them up with fine grit sand paper and coated them in dielectric grease. See if you can find a wiring diagram for the car and you should be able to see where the grounds are in the engine bay. Hopefully that will help some.
posted by ganzhimself at 8:03 AM on November 13, 2010

I had a similar experience and it turned out that, when I reattached the battery cable, it didn't tighten down fully. It would work for a few starts, but then something would jar it loose or it would just fall out of contact and I'd have a dead car. Making sure the cables were tightened down and connecting well fixed the problem.
posted by katemonster at 10:34 AM on November 13, 2010