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A valuable lesson in testing voltage drop

Tuesday, January 30, 2018 - 09:00
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I heard the familiar rumbles off in the distance. It was summertime in central Florida. I was near the middle of an area that’s called “the lightning belt” — an imaginary line that can be drawn between Tampa and Jacksonville. It’s called this because it is said to have more lightning strikes per year than any other place in the Northern hemisphere. The weatherman said there was a good chance for a thunderstorm that day — and this time it appeared he was correct. The sounds continued to get louder as the storm got closer. Having lived in Florida nearly all of my life, I paid only a little attention as this is an “almost every day” occurrence. 

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The Pontiac Fiero’s engine had been disassembled earlier in the day and the car was left outside to accommodate the service bay for other work while we waited for the delivery of the parts needed to reassemble it. With the approaching storm’s arrival sure to beat the parts driver’s, I pushed the car inside the bay just enough to where any rain that might blow in wouldn’t cause damage to the exposed components.  The wind started picking up and since it was close to the garage door opening, I started protecting the car’s engine compartment with plastic sheeting when….. 

I woke up on the garage floor beside the car! I could see the undercarriage as well as the tools on the other side. I couldn’t move. There was a loud ringing in my right ear. I took a deep breath and could smell something had burned, but couldn’t place what it might have been. It wasn’t like plastic or wood, just an unfamiliar smell of something that burned. I felt tingling all along my right side, including the right half of my tongue! Finally, I could move my right arm (was lying on my left side) and in a few minutes was able to sit upright. I gave a quick visual inventory of my extremities; all were intact, then looked around, still quite dazed, but had the wherewithal to know what just happened. I had been struck by lightning! 

I’m thankful it wasn’t a direct hit. In fact I’m sure if it had been, I wouldn’t be sharing this with you today. Judging from the damage the strike caused, I’m certain it would have killed me. Every phone wire, phone jack and telephone in the building was destroyed. The TV was no good anymore. The submersible well pump on the property, hanging on over 60 feet of pipe, was destroyed as was the pump at a neighbor’s home some 200 yards away! I have since forgotten what else was affected in that one-second-long event but I’m sure you get the point. 

Not my truck, not the original color, but the Ford Lightning pickup I ended up working on had been around from shop to shop, even making appearances at a local dealership. The initial complaint seemed simple enough: no start, no communication and no odometer. Then why did the dealer technician toss his hands up in surrender after a month and a half without a solution? It's all about a testing method we've preached about before - voltage drop

A different kind of lightning 

Can you imagine what my initial reaction was when years later I received a call from an owner desperate to get his Ford Lightning running? I had a flashback to that fateful summer day momentarily, but regained my composure quickly enough that it went unnoticed. His truck had stopped running unexpectedly and would not restart. My notes of our initial conversation include, “Owner has a Ford Lightning, the Powertrain Control Module (PCM) has failed (per Ford dealer’s findings). The truck shut off, would not restart and has Passive Anti-Theft System (PATS) Diagnostic Trouble Codes (DTCs). He has another PCM he bought from Ford that needs to be flashed but Ford was unable to perform the task.” 

As a mobile technician, I come across all kinds of unusual scenarios that aren’t commonly seen in the stationary repair shops. “The engine quit running while being driven,” the owner said when I arrived at the location to where the dealership had towed the vehicle, and “it has been to a dealership for analysis. The PCM was condemned and must be programmed to the vehicle.” He wasn’t sure why they couldn’t do it, or pretended this very well, and handed me the “new” PCM and the box from where it had been removed. 

Without elaborating unnecessarily about all the details, I learned one of the reasons why Ford wasn’t able to complete the repairs on it. There was a “problem” with the Vehicle Identification Number (VIN). I learned the truck’s cab had been replaced, but the original VIN had not been transferred to the replacement. Therefore, the VIN displayed on the door label and viewed through the windshield (1FTRF07263KB98749) really didn’t belong to the rest of the vehicle — so the dealership probably refused to perform any more repairs once this fact was acknowledged by the owner. This VIN is for a 2003 Ford F-150! I was reconsidering the reasons why I chose to be a mobile tech at this point! 

The PCM is mounted inside the vehicle, on the right side kick panel above and outboard of the blower motor.
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