know-it-all customers

We had a customer come back in today, claiming his system was all f---ed up and that he had engine noise.

We had installed a Kenwood four channel amp in his Buick Regal with the factory deck this past weekend.  This amp powered the fronts, as well as a sub.  With the volume all the way down, you could hear engine noise. 

My fellow installer who hooked it up on Saturday had me help him look it over.  We first checked the ground, and since it wasn't tight, redid that.  The noise was still there.

We decided to check the gains next.  Any slight turn of the volume knob, and the system would blast.

Someone had apparently turned the gain controls 90-95% of the way after we had installed it on Saturday!  No wonder he had noise.  We reset the gains and no more noise.

I told the salesperson that we needed to charge that customer for tampering with our install (minimum $45), so he asked me to speak with him when he came back to pick it up.  I agreed.  I hope he charged him, because I didn't hear about it again after that. 

Even though it only took 5-10 minutes of my time, it rubbed me the wrong way when the customer tried to pawn off his blatant disregard for our install as our fault.  That stuff can make your blood boil.

I had that to many times, so i put little stickers over the gain control so if it was tampered with, the install warranty was null and void.

This isn't a "know it all customer," problem, it's a problem with expectations. You fixed it, which is good, but did you educate the consumer as to what the gains are for?

The stickers sound like a good idea, but taking the time to explain the system you installed would also reap dividends in terms of both avoiding problems, as well as increased customer satisfaction.

I've got an EE background and I'm sure I come across as a "know it all customer," too; far too many of the installers I've spoken to in person are just knucleheads, and they don't understand why I won't just blythely drop $4k into a sound system because they think it rules or it's what they happen to sell. Not to mention tearing apart my car

There's nothing wrong with us disagreeing with each other.  I can see your point, but the guy had to take the cover off the adjustments with an allen wrench to get to the gain controls.  I'd say that qualifies him as a "know-it-all" customer, because he obviously thought he knew much more about it than us.

No, unfortunately, I never had the chance to meet this person.  I was actually looking forward to it, since the salesguy didn't want to explain to him why he needed to pay us a service charge.  We make it apparent to our customers that our installations come with a lifetime warranty, and that if any problems arise, we'll take care of them, but they have to give us the opportunity first.

I don't doubt that you know your stuff, and have also come across too many bonehead installers.  I think all of us have.  I'm not in the business of pressuring people into buying things they don't want.  That's the salesman's job (j/k).  Seriously, I'll give my opinion if you ask for it, but I'm not there to twist anyone's arm.  Ultimately it's the customer's decision to make whether or not they want to spend money and on what.