The illusory repair powers of black electrical tape

Date:June 29, 2010 / year-entry #188
Tags:non-computer
Orig Link:https://blogs.msdn.microsoft.com/oldnewthing/20100629-00/?p=13573
Comments:    16
Summary:Back in the crazy dot-com boom days, I knew someone who was into high-performance automobiles. And since these were the crazy dot-com boom days, he had the money to satisfy his urge to drive high-performance automobiles. He bought a used Ferrari, but found that it spent more time in the repair shop than on the...

Back in the crazy dot-com boom days, I knew someone who was into high-performance automobiles. And since these were the crazy dot-com boom days, he had the money to satisfy his urge to drive high-performance automobiles. He bought a used Ferrari, but found that it spent more time in the repair shop than on the road. To solve this problem, he bought a second Ferrari. (Note: This is not a solution available to most people.)

One of the many trips to the auto repair shop was to address an indicator light on the dashboard which had lit up. The mechanics studied the problem and concluded that the indicator light was a false positive. There was nothing wrong with the car aside from the light itself. "Just ignore it," they told him. "We can't disconnect the light for «some reason». If it really bothers you, you can put a piece of black electrical tape over it."

"I don't accept that solution," he replied, and told them to go and fix the problem for real.

Some time later, he returned to pick up the car, and yes, the indicator light was off. Satisfied, he drove off.

The next day, he took a closer look at the dashboard. The repair shop had cut out a piece of black electrical tape in the exact shape of the indicator light and placed it over the malfunctioning lamp.


Comments (16)
  1. Time to find new mechanics.  Wonder what else they papered over.

  2. laonianren says:

    What's the world coming to?  Any competent bent mechanic would have cut the wires to the indicator light.

  3. SMW says:

    This is/was a regular thing that some BMW drivers would do for their dash-based oil change indicator lights.  Resetting the light required a tool from BMW that plugged into a port under the dash.  If you got your car serviced at the dealer, they have the tool and would reset the dash.  If you went to an independent shop, they probably didn't have the tool, so the light stayed on.  Simple solution for 'turning off' the light: electrical tape.  Knowing when to get your oil changed again was done via the sticker placed in the top corner on the inside of the windshield… no need for the light.

  4. Tom says:

    SMW, I remember that.  That light was on the whole time I owned that old car… never considered trying to cover it up.  Then again, the instrument panel only worked around half the time anyway.  Good times.

  5. Carmen says:

    laonianren: If it is a sealed instrument cluster, it could involve taking the whole dashboard apart, prying open the sealed cluster (and possibly breaking things) just to cut a wire.  In those scenarios, black electrical tape is the better choice for everyone involved.  It could have literally cost thousands of dollars in parts and labor to cut that wire on a Ferarri if something went wrong.  

    Raymond's acquaintance sounds like a coder.  To a coder, anything can be fixed properly and easily with some new code.  In the physical world, that doesn't always work out well.

  6. Falcon says:

    Earlier this year, I was looking up instructions on how to remove the instrument cluster from an Opel/Vauxhall/Holden Vectra. A common fault with these cars' Triple Information Display is that some pixels/columns on the LCD stop illuminating or flicker randomly – loose contacts, I believe.

    Well, one person who posted such instructions said that they had got sick of looking at the broken display, so they just left it disconnected when reinstalling the cluster! (I was going to try to fix that while I had the cluster out, but the case proved a little difficult to open, so I just left it alone. However, it seems to have come good all on its own over time!)

  7. David Walker says:

    My car's oil pressure light comes on (and it flickers, like it's trying to barely come on) when the car gets hot and the engine speed goes down to idle.  The problem is not that the car's oil pressure is low, but the oil pressure sending unit has a known, documented problem when the car gets hot.  The real solution, spelled out in a service bulletin, is to replace the oil pressure sending unit with one that isn't quite as sensitive.

    So, as long as the light doesn't come on solid when I first start the car, I know that the oil pressure is probably okay — I haven't decided to replace the oil pressure sending unit yet.  Occasionally, a friend who is riding in the car will tell me that my oil pressure is low, and I'll say "no, it's really not — the instrumentation is defective".

  8. Danny says:

    I don't get it, why is the link to ATM vs voice-mail past entry? What is the connection between these 2 blog entries?

  9. Falcon says:

    @Danny: Look at comment no. 6, by Joe Dietz.

    The URL is supposed to take you directly to that comment, but that feature doesn't work since the site upgrade (as several people, including Raymond, have pointed out so far).

  10. blah says:

    Fix It Again, Tony! Only way more expensive and deadly.

  11. Mordachai says:

    @Carmen – even in software there is not always (or even often) a simple easy fix to a problem by just recoding some code… often, in my experience, it introduces new shortcomings, interactions with old software, mixed environments, old OSes, etc., ad nauseum, such that for every attempt to fix a thing, there is often an unexpected problem created.  That's overstating it a bit – but only a bit.  Software coders think everything can be fixed with a few lines of code… and they're (often) wrong.

  12. rsola says:

    This reminds me an episode from The Simpsons. The family is in the car and a noise starts to sound. Lisa realizes a warning sign that is flashing on the dashboard and Homer puts some duct tape on it. Then the car stops after a while, precisely at the Springfield Retirement Castle where Grampa is waiting them.

  13. Anonymous Coward says:

    :-) I regularly tape over power-indicator leds on devices. Much easier than removing or shorting them and this way they're still there for the unlikely circumstance that you'll need them.

  14. Mike Dimmick says:

    Nigel Stuke: Mechanics need to get the heck up to date. Cars have been more about electronics than rubbing components since electronic fuel injection was introduced (early 90s?) Electronic throttle and electronically-controlled brake-force distribution are more recent additions but are appearing on a wide range of cars.

    On the Prius group we see a lot of US post-2006 owners covering up the tyre pressure monitoring light, because the mechanic broke or didn't properly re-seal the TPMS sensors when they got their tyres changed. Art's Automotive wrote a great article about TPMS:

    http://www.artsautomotive.com/…/81-tpms-tire-pressure-monitoring-system

    I'd prefer a $1,000 diagnostic fee to a $4,000 replacement transaxle, and still have the problem not fixed! If there's a problem serious enough to log a Diagnostic Trouble Code, which causes the Check Engine light to come on, the car's service manual has a diagnostic tree of things to test. It seems that frequently the dealers don't actually follow this but just replace the most expensive component. It shouldn't take 10 hours to rule out most of the causes for failure.

    To that I would add checking that the chassis ground points have good conductivity – a poor connection causes a voltage difference between different ground points. This can cause an ECU's read of a sensor value to be different to what the sensor thought it was reporting, if there's a voltage between the ECU's ground point and the sensor's (or if different planes in the ECU have different ground points!)

  15. Matt says:

    Mike Dimmick: You may be fine paying a $1,000 diagnostic fee but many wouldn't because they would think of it as paying that much money to find out that the light they can see is on. Nigel was spot on in the potential repair route, while you mentioned the Prius TPMS sensor may be a common issue with a simple fix it's often not the case. A sensor reported problem could be anywhere between the sensor and the computer and it's not easy or cheap to fully test or replace this systems. I've seen a car with intermittent fuel pump problems have it's fuel pump, computer, and much of the cars wiring replaced (both new and borrowed from known working cars at huge costs) still have intermittent fuel pump problems.

    My daily driver currently has three dash lights on because one sensor is intermittently not working, I haven't yet fixed it for two reasons: it doesn't affect the safety or functionality of the car, and the sensor is extremely cheap but embedded in an extremely expensive part and cannot be replaced individually. Though I don't use tape, I just don't pay attention to them anymore.

  16. Nigel Stuke says:

    When I used to work on cars, there was a technique we had called the "shotgun approach" for these scenarios. There *MUST* be something wrong somewhere that is causing the light to come on. It could be an electrical short, a bad computer, or a bad sensor somewhere. Diagnosing this properly could take tens of hours, and no shop will try to sell you a $1,000 diagnosis fee. If someone really want something like this fixed and has enough money; even without the proper diagnosis if you replace enough parts eventually you will fix the problem. The salesman just needs to be very clear in his wording that a) replacing part 'a' may not fix the problem and b) you're still paying. The more likely problem is that the mechanics don't feel comfortable with electronic components….

Comments are closed.


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