Occam’s razor, our Maxima, and the Sage Mechanic

Posted on January 15, 2017 Updated on November 29, 2023

My wife has a Nissan Maxima and loves her car. Over the past 9 months, there has been a persistent but seemingly random problem where the radio is used for a few minutes while the car is off and then the battery dies when she goes to start the car. This has happened more than a dozen times over the past 3 1/2 years, and it has been seen by two dealerships for a total of three times recently with no success – the most recent visit being one day before this problem occurred.

Saturday morning, I was running errands when my wife called and let me know that this problem had happened again (the second time this week, and she was very frustrated). I was pretty excited because this time, the problem occurred at home, not at some parking lot like usual, so I had the luxury of time to try to make a root cause determination. I’m somewhat mechanical but no professional, so I followed my consulting advice and contacted a professional.

Dave T. is a mechanical guru with an uncanny ability to offer sage advice with only a modicum of information. He is incredibly busy but always willing to spend a few minutes and give helpful advice. It helps that he is a great guy, but it also helps him generate business (leads and referrals). It is an approach that helps create a constant backlog of work and a very loyal clientele, which is good business.

I called Dave, described the problem, and mentioned what I had read on various forums (i.e., similar electrical problems observed after some arbitrary mileage). Next, I mentioned that this had just been to the dealership, and they did not find anything wrong. Dave laughed, stating, “There is a 99%+ likelihood that the alternator is bad, possibly both the alternator and battery.” He sounded very confident.

There was a pause, and then he asked, “What’s more likely – that there is some completely random problem that only happens when your wife is out and your son stays in the car and listens to music for a few minutes, which by the way only happens to Maximas after X number of miles, or that there are issues with the alternators where they tend to fail after a certain amount of use, which causes them not to charge the battery properly and leads to a condition where there is not enough of a charge to start the car?”

When Dave explained it like that, I felt kind of stupid, consoled only by the fact that other professional mechanics had not resolved the problem before me. He added, “Anything that could drain a battery within a few minutes would be noticeable. It would start a fire or melt wires and smoke or smell. You haven’t seen or smelled anything like that, have you?”

I described my plan to troubleshoot the problem, and Dave suggested that I also test the alternator and the specific gravity of the individual battery cells. So, less than five minutes into that call, I had a plan and was off and running.

Yesterday afternoon I spent several hours using a methodical approach to troubleshooting, documenting everything with pictures and videos to help me recall details and sequence if needed. Sure enough, Dave’s knowledge and intuition led to the correct conclusion.

I called him to thank him, and while talking, I wondered aloud why the dealership could not figure this out? Dave replied, “It’s not that they couldn’t have done what you did, but instead, they focused on the symptoms you described. The mechanic probably sat there for 10-15 minutes with the lights and radio on while the car was off. After that, the car started, so they assumed everything was fine.

I listened to what you said, ignored the randomness and speculation, and honed in on the likeliest problem. The fact that this happened again so soon also made sense because now your battery was run down from the testing performed by the dealership.” He added, “In my business, I get paid for results, so I can’t get away with taking the easy way out.” 

I’m big on lessons learned, wanting to make the most of every experience because I have learned that skills and knowledge are often very transferrable. As I thought about this, I realized that Dave’s analysis was the perfect practical application of Occam’s razor. It’s a very helpful skill as a Consultant, but more importantly, it can help when problem-solving in any line of work.