I talk to car guys a lot and it seems that they have the hardest time with troubleshooting electronics. Many of them have a multi meter but that some times leads in to greater confusion. I have been thinking about developing a simplified tester. The idea is that if you were measuring voltage the readout would say 13.6 volts DC. If you were measuring resistance it would say 3.4 ohms. It would switch functions by itself so if you probed a wire and it was ground it would show resistance and light up a continuity light. If you probed a wire that was hot it would show voltage.
A ground checker function would let you check to see if there was too much resistance between the say tail light socket and the body of the car.
A connection tester would look for poor connections. (thinking bad connection at battery terminals)
I would like to add short finder as an included accessory that injects a signal that the meter could sniff out. (You would follow the signal down a wire until ti stopped, showing where the short was located.) This would be hooked up at the fuse block location where the fuse was blowing.
In plain language what would you like to do? This would have a modern back lit display and rechargeable battery.
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Interesting idea. I know that there are devices for fiber optic cables that sniff out where the break is, but I’m sure it can also be done for copper wires. The problem is that the amount of time for voltage to travel down to the break and back is nano-seconds, and that complicates the meter’s simplicity. I also know of mho-checkers, which measure micro-ohms for poor continuity, but again, those are highly specialized pieces of equipment.
Personally, I prefer resistance over other measuring techniques, as there can be stray voltages which confuse readings. The only problem with relying upon resistance by itself is that it can fail to detect the ability to transmit sufficient current.
I’d be interested in helping you out exploring how to best construct a simple tool.
Randy
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Thanks Randy! As i get further along lets talk.
I think an infrared thermometer would also be useful.
I want to build the Gauge tester in as well.
How about a sender tester. You would hook an alligator clip to the sender and it wold show you what the gauge reading should be. (think of a simulated gauge display.
You’re pretty much describing a Power Probe. It has most of those functions built in. Some of the higher end versions have scope capabilities and other functions.
TBH, tutorial videos showing people how to diagnose common problems with common tools would be the most beneficial. Many think of electricity as some sort of voodoo magic and just fire part after part at the problem rather than invest the time in noodling through the issue.
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Electrical might as well be vooddoo magic. Car guys tend to be good at looking at things and figuring out how they work. You can’t do that with electrical problems. What needs to happen is that the tool needs to provide answers not data. The gauge tester lets you test your gauges and confirm the function of the instrument voltage regulator without ever learning what OHM means. People love it because it answers the question: Is that gauge reading right?
What? You mean that electricity is not voodoo magic? Since when? You mean I have to give up my voodoo car dolls??? G
Interesting idea Bill! For me, the more fascinating part of electrical engineering is troubleshooting things that don’t work as expected. You kinda have to think like an electron, which isn’t very intuitive - lol! But it does seem like that could be accomplished with enough measurements and a small microprocessor.
I guess I’m old, the trusty test light(incandescent) and a fluke 87 can do pretty much everything needed.
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I do as well, or my best friend the power probe that combines both those tools and then some into one tool. Being able to apply power or ground to a circuit without hassle is a huge bonus on the power probe.
I think its a good idea, I do wish more would invest the time to learn how to diagnosis then look for a tool that just tells them the issue, however some days Im sick of the diagnosis and learning and just want my scan tool to tell me whats wrong!
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This would not be a tool for any one that really understands electrical work. Any one that owns a John Fluke anything already knows what to do. I am trying to listen carefully to what guys are asking me. The hobby is supposed to be fun and if folks are getting frustrated by electrical issues then that takes the fun out of it.
And this may just be a pipe dream as I have a feeling that it will probably be fairly expensive when I get done ($200?) and that might make it unsaleable. It may be that the power probes and multi meters are what they are because that is what the market will pay for.
Let me try to explain the thinking. Background: I rebuild and calibrate fuel sending units. I rebuild a unit and test it and the customers gauge still doesn’t go to full. I can tell the customer that you need to get a 10 ohm resistor and substitute it for the sender and the gauge should read full. Not going to happen. Or I tell them to use a multi meter and measure the resistance across the sender pin out and ground. The meter ends up on the K ohm range and the are wondering why it shows.01 ohms. Or the meter is a $6.95 special and it won’t read low impedance with any accuracy at all. Now if you are an electronics guy you might have a decade box or a linear 100 ohm pot and know how to do all of the testing. What I did was to remove the electronics jargon. The tester has a 3 position switch for full, 1/2, and empty. You unplug one wire and hook up two clip leads. Easy peasy.
SO what I am thinking is that if you wanted to test your sender the display would show some simple instructions at the bottom. It would tell you where to hook up the test leads. Then it would show a simulated gauge that would show you what the sender put out in terms of gauge reading and not ohms. I have thought about doing a little Bluetooth device that you could leave connected under the hood so you had a wireless gauge.
For voltage and resistance it needs to be auto ranging with a display that shows when the battery is charging (above 12.6 or so volts). And if checking a ground might show resistance is too high above about .75 ohms. Again the display would have simple instructions telling where to hook up the leads.
With lithium batteries the power probe function doesn’t have to be powered by the car so we can dispense with those long leads for battery hook up. It should be practical for the display to show what you have found (power or ground and values for each) and then allow you to inject power or a path to ground. Again simple on screen instructions will be key.
A non contact thermometer is a good example where instructions are key. People often fail to realize the place you need to measure temperature at is at the temperature sender. Other places are useful but if you are trying to see if the car really is overheating this is where you start.