Q. What is the weirdest problem you've ever encountered, and fixed?
_ Zach K.
A: There have certainly been many odd situations through the years that can make one realize there is so much more to learn, and symptoms and failures can occur under the most odd circumstances.
It was 1988, I was the technical foreman at a Pontiac dealership. I got this position by showing interest in drilling really deep for information, studying service manuals, technical service bulletins and calling for technical assistance when things got hairy.
The car was a just-sold Bonneville SSE, a fresh design, with complaints of the CD player changing tracks randomly, among some other odd symptoms. I drew the job and, try as I might, I couldn't duplicate any of the symptoms. I probably put 50 miles on the car under every imaginable condition.
After checking all related connections, we reluctantly returned the car to the customer. Sure enough, the symptoms returned, and the customer was growing increasingly more upset. I road tested over bumps, under power lines, under hot and cool conditions, smacking the dash _ everything I could think of _ with no success. I worked directly with the customer, discussing symptoms and road testing together, showing empathy for his concerns. This helped a lot to maintain his trust.
This was Pontiac's first stab at steering wheel controls, using tiny infrared lights and phototransistors to pass signals between the rotating steering wheel and the stationary steering column, allowing a multitude of different commands to be passed through from the many steering wheel buttons (subsequent vehicles use a ribbon cable clockspring).
I opened a case with GM Technical Assistance, and they suggested I replace the "translator module," a gadget that processes the light pulses and passes signals on to various modules. Again the car returned. Desperate for a fix, I swapped all other related parts with an identical new unsold car outback (officially a no-no), as our customer was heating up and starting to talk buy-back.
This still didn't fix it! This time I drove the customer home in order to make yet another try. I thought I'd scope the vehicle's electrical system for possible voltage spikes. I wasn't sure what else to try.
It turns out the gentleman lived in a mansion-like home with a very long driveway lined with very large trees. As we came up the driveway the CD player and A/C system went nuts! I looked up at the open sunroof and flickering shadows and it hit me: I had never driven with the sunroof open. I laid a shop towel across the top of the steering wheel/steering column junction and the symptoms absolutely subsided during a dozen or more driveway trips. Apparently the flickering ambient light was reaching the photo transistors and was mimicking various button commands.
I reported back to Technical Assistance and they got the engineering folks working on a plastic shield to be mounted inside the steering column. During the time it took to get these designed, fabricated and installed, our gentleman was cool with draping a bandana across the column whenever he used the sunroof.
