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Automotive electrical battles won

Monday, July 1, 2019 - 07:00
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When I mention “electrical” problems, I’m not referring to electronics. That’s a different topic all together in my book! To me, electrical is typically anything that’s not involving a computer. To clarify more, electrical may include the wires and terminals leading up to a module, but not necessarily the module itself. We’ll have opportunities to share war stories involving faulty electronics at some point in the future.

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At almost every automotive training class I attend — and at the ones I present — at almost every trade show and at just about every technician gathering, it is inevitable someone will share (with anyone who will listen) a diagnostic dilemma in which they are currently involved or had recently encountered. It is in our nature to share them I think, but not so much to beat our chests (in most cases), but instead to possibly learn how better we can diagnose such a problem in the future. In almost every case, you’ll hear how much longer the solution took to find than the story-teller thinks it should have, had they encountered something similar previously.

Once disassembled, it’s obvious the electrical contacts could not conduct well, much like a starter solenoid’s contact disk that is worn.

I’ve not seen everything there is to see and I pity the poor soul who thinks they have when it comes to automotive electrical problems. I attend as many training events as I can in part to hear other people’s war stories. My feeling is, if it happened to that person, it will likely happen to me as well and when it does, I’ll have an advantage – that I learned how it was solved without suffering the pain and agony that the other person went through! I am a member of many automotive technician websites for the same reasons.  There’s no logical reason for me to work harder than I have to. Is there one for you?  

In my classes I try to emphasize the importance of understanding the concepts, the strategies and the principles of operation rather than to focus on how any one manufacturer has applied those to their products. What I mean is, for example, it’s great to know how a GM TPS (Throttle Position Sensor) works, and it’s important to know how to properly test it. It’s as important to know where each one may be located on the various applications ONLY if the majority of vehicles on which you work are manufactured by GM.

However, most of us do not work on only one brand of vehicle. So, if you know the principles of operation for a GM TPS, for example, then no matter which manufacturer employs a similar device, you should still be able to apply the concepts learned about the GM TPS to the one you are working on today. There are rare exceptions but a majority of TPSs, a majority of starters, a majority of fuel injectors (etcetera) — all share the same concepts. Master those concepts and apply them to whatever you’re fixing today to be considered a great diagnostician!

Applying electrical principles

I recently had an opportunity to put my own instruction to the test on a non-automotive application. Some good friends, a married couple, had called a residential heating and air specialist because their home HVAC (Heating, Ventilating and Air Conditioning) unit would blow air properly but not always at the correct temperature. The HVAC technician spent less than a half an hour after arriving to inspect the unit before presenting my friends with the recommendation to replace the whole thing. He claimed it was very old and inefficient and said he’s not familiar with that brand, then said he wasn’t trained on them anyway. It didn’t cost anything for his service call nor for his writing an estimate for replacing the unit (thankfully!). I suppose we consider 1999 cars as “very old,” which is the same year this HVAC unit was produced. I’ll give the tech that much.

When my friends told me of their dilemma and what the tech had said, I just shook my head in shame, knowing a lot of automotive technicians say similar things to owners of vehicles on which they were not trained. The HVAC technician could have applied the same concepts he knew to this (well-known) brand, but apparently didn’t have confidence in his skills to attempt such a thing. It seems more of us at least attempt to apply the principles of operation on vehicles we may not be familiar with.  The HVAC technician never even tried.

(Image courtesy of Mitchell 1) It was rare to see isolated circuits when you wanted to look at a wiring diagram for a vehicle in 1980. This diagram is four pages — for the whole vehicle!

Being the brave soul that I am, I told my friends I’d look at it and see what I can do. I started by researching the complaint for the brand and model on a few DIY home repair and HVAC websites. I wanted to see if there was something that went wrong commonly with units that were similar to my friends’. This is no different than one of the first steps I’d perform when researching an automotive problem on a brand with which I was unfamiliar. Do you use websites like iATN, Identifix, Diagnostic Network, etc.? I find these extremely valuable especially under the same circumstances.

I didn’t have any good luck. There weren’t enough identical complaints/fixes for me to condemn any particular component based on a common problem. There were no silver bullets for me here. I had to consider doing what a good HVAC technician might do – diagnose it!

My research led me to the manufacturer’s website where published were the complete wiring diagram, the Owner’s Manual, a Quick Start Guide and get this, an installation manual complete with a troubleshooting guide! How about that? This very old unit has built-in troubleshooting complete with blink-out codes!

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