You Can Lead a Horse to Water…
As a technician I work on symptoms of a problem, diagnosing said problem, and then make the appropriate repairs. It's hard to
justify going out into the service bay and installing parts that a
customer swears up and down is the cure to their aliments.
The point being, I haven't diagnosed it. I haven't verified the
complaint, nor determined if the part in question is at fault.
It happens all the time, a customer will read something on a forum,
talk to their friends, or perhaps they’ve gone to one of those parts
stores that will code your car for you. You know the parts stores
I’m talking about, the ones that carry every part from A to Z, the
DIY’rs first stop when it comes to any kind of repair. I really
think it's not wise to give partial answers to unsuspecting customers
who will only take those “codes” and assume that a particular part
is the problem, because it was mentioned in the description of the
code.
Which leads to the eventual problem at the service counter. Here comes “Mr. Customer”, armed with that tidbit of information
which he has committed to memory. Now he's trying to lead me down that path where he thinks I’ll be so happy to oblige. In some ways it's like the proverbial horse being lead to water. The usual scenario starts off with me asking, “What can I do for you today?”
“I need my GEM module replaced, how soon can you do it, and what will it cost?” the customer will ask.“Well sir, I could give you prices, but I'd like to know how you arrived at this conclusion, before we just start stacking parts on top of a problem,” I told him, “How about we begin with what doesn't work in the car, instead of what part we assume needs changed.”“My wipers don't work, my power windows don't work, and my radio doesn't work. It blew the fuse once,” the customer tells me, “the fuse is marked GEM, so I know that's the problem.”I wouldn't dream of going to my doctor and telling him, “Put me in a new kidney.” A smarter approach would be to tell the doctor the symptoms I'm having, rather than tell him what I think needs to be done.“I have a battery drain also, and I know it's not the battery or the alternator,” the customer goes on to tell me.“There you go again sir; you're leading the symptom with a result before it's even tested. How about we just start with “It blows the GEM fuse, and I have a battery drain.” Once I had the vehicle in the service bay, I did some checking on all the systems he had mentioned. The wipers, radio, and windows all worked perfectly no… blown fuses, no “GEM” problem noted. Although there are a few things I will check when someone comes in mentioning something to do with the GEM module, and that's check for water damage on or near the fuse box. Luckily for this guy... it was dry, and no signs of any water or mineral stains on it. The next step was to check for any parasitic draws... none. OK then, might as well check the two things he said it wasn't. Hmm, the battery didn't pass load testing, and the alternator has a rather low output. Well, well, well... seems a little diagnostic work really did pay off this time. No surprise to me, but it sure was to him. Arm chair diagnostics hardly ever amount to much. This was no exception. I did explain to him how everything requires proper testing to determine the cause and cure for a problem. Even though I couldn't rule out the GEM module as the problem, he did get the idea that a number of other factors could cause the fuse to blow. “I'll keep an eye on it,” he told me.Some people think they are actually helping the technician by telling them which part needs replaced. On the contrary, that’s completely the opposite. I always picture a horse with blinders on when a customer tells me the exact component they want replaced. I need to see the whole picture, and not just what they think it is. Most of the time the true answer isn't as clear as changing a component, but a lot of these “helpful code reading parts stores” tend to inform their customer that it's just that... “Change this part, and you'll be as good as new,” the A to Z parts store guy will tell them. Then what does the customer tell me when they get to my shop? “Change this part; it'll be as good as new. I've been told that already by my mechanic.” Seriously people, ya need to rethink this a bit more. Codes don't fix cars... technicians fix cars; they just use the codes as the road map to solve the problems. An example of reading codes and coming up with the wrong answer happened a few days later. This time from a guy who insisted that his 95 Dodge computer is locked up. “Locked up, what do you mean by that?” I asked.“My mechanic said it's in “auto shut down”, so I need to know how much you'll charge to put another one in?” the caller tells me.I'm not sure who is leading who here. Is this guy's mechanic leading him into believing something is wrong with his PCM, or is the customer leading me into changing a part based on some nitwit’s evaluation? (Probably both) I'm well aware of how the ASD relay works with the PCM on these Dodges, and I'll bet this is what he's referring to as far as “locked up”, but I could be wrong. Of course diagnosing and testing is the answer here. “My mechanic said it's either a timing chain or the computer that's bad,” the caller goes on to say.“Sir, my best advice to you is to remove your car from there... if your mechanic can't tell the difference between a timing chain problem and a PCM, you've got a more serious issue than your car’s problem.”Needless to say, even mechanics can fall victim to the horse with blinders routine. Sometimes it's harder to ignore the advice of others, even when you know you should. People with the best intentions can have the wrong answer to an automotive problem, and they'll do everything they can think of to lead the technician down their path of poor choices. Every tech I’ve ever met has had this happen to them a time or two. Past experience does pay off and makes you a little more cautious when dealing with similar issues. Just like the horse,… you can lead it to water… but you may not get the results you’re expecting. 
