Voltmeter in place of Ampermeter August 15, 2012, 03:05:52 PM As you know, ampermeter in the cluster is totaly useless feature, because it doesn't work on most cars and even when it works, it shows bullshiznits. That's the reason, why I decided to convert one spare fuel gauge to voltmeter.I peeled off the Amp gauge dial and sticked it on the fuel gauge. Viola....These photos were taken during the calibration process, that's the reason why the needle is on "C" mark.Off course, this gauge needs external controller. I prefer Atmel Atmega microcontrollers, so I used some chip from my drawer and made a very small circuit containing almost only the microcontroller, trimmer, power mosfet with anti-parallel diode and the small LCD screen for PWM readout.I'm going to control all four gauges with this system in the future. Stay tuned...PS: The gauge doesn't have any numbers on it, but in the center is 12V and space between marks is equal to 2V. That means, that I have 8 - 10 - 12 - 14 and 16 V marks. Quote Selected
Voltmeter in place of Ampermeter Reply #2 – August 15, 2012, 08:58:24 PM as much as i love your project ,, why wouldnt you choose an already made volt guage? instead such as one you could simply tap into the interior primary ?>I am doing this project now myself (getting the parts together but the guage will have a tiny rotary switch with at least a dozen positions that can be rotated to monitor anything i want such as:pos 1- normal position reading alternator output as close as electrically possible to the alternator outputpos 2- reads as close as electrically feasable to the batterypos 3- reads the 5v that is developed at the instrument cluster IVRpos 4- reads the ignition switch supply power pos 5 through X will be used to read power after selected fuse links up near the starter solenoid.The reason i am doing this is because it would be helpful in troubleshooting.One additional adder i am doing is swapping out all my fuses for ones that have LED's so i see which fuse is blown!!!With these two small inexpensive steps, it gains you soooo much more time in nailing down the trouble shooting steps and circuit isolation.I plan to place the tiny rotary switch in an area easy to get to area but out of sight. Quote Selected
Voltmeter in place of Ampermeter Reply #3 – August 17, 2012, 09:12:01 AM A fuse with led warning? I have never heard about this before!And a reason why I'm doing this instead of buying a couple of 52 mm gauges? Because I don't like them. I don't want my car be looking like some ricer. It will be a sleeper!The last idea is to change all the small gauges to be equipped with a small servo for RC models. It should give them the right accuracy. But this is quite a long way and I don't have so much spare gauges :-( If you have some spare TC cluster, you can send it to me :-). Quote Selected
Voltmeter in place of Ampermeter Reply #4 – August 17, 2012, 10:44:33 AM i just got my LED fuses, yea they exist what i meant is use an aftermarket volt meter and transfer the ammeter face on it just like your doing in place of the old ammeter. Quote Selected
Voltmeter in place of Ampermeter Reply #5 – August 17, 2012, 05:55:12 PM Trinom!!! I love mods like what you are doing. That is neat and very ingenious. Another words JAKE!!! Quote Selected
Voltmeter in place of Ampermeter Reply #6 – August 17, 2012, 11:17:06 PM Quote from: TOM Renzo;396197Trinom!!! I love mods like what you are doing. That is neat and very ingenious. Another words JAKE!!!Agreed, I'm jealous I didn't think of such a mod... Quote Selected
Voltmeter in place of Ampermeter Reply #7 – August 17, 2012, 11:38:04 PM I used a hacked up GM voltmeter in mine. This should be a neat trick!Good luck on it! Quote Selected
Voltmeter in place of Ampermeter Reply #8 – August 22, 2012, 09:00:44 PM I am having trouble converting my amp gauge to a volt meter, must have the wrong size caps/resistors internally.all the other guages total resistance reads 12.5ohms but this one reads zero resistance. I know its intened purpose is to be reading across a shunt wire, the problem here for me is that i "want" it to take in 12v that way i can integrate the rotary switch i picked up to select various other circuits for trouble shooting purposes. why not have a built in volt meter to help you determine electrical problems.all these buttstuffog small meters are designed to be taking in 5vHope your project is going well man,mine is going to have to be a 12v based system though , much different than your application so i will likely be forced to retrofit the internals of an aftermarket guage into the housing of the oem cluster housing. Quote Selected
Voltmeter in place of Ampermeter Reply #9 – August 28, 2012, 11:15:53 PM Quote from: jcassity;396475I am having trouble converting my amp gauge to a volt meter, must have the wrong size caps/resistors internally.all the other guages total resistance reads 12.5ohms but this one reads zero resistance. I know its intened purpose is to be reading across a shunt wire, the problem here for me is that i "want" it to take in 12v that way i can integrate the rotary switch i picked up to select various other circuits for trouble shooting purposes. The modification uses a FUEL gauge with the ammeter face replacing the the original...Even that isn't as easy as it would seem at first thought, as the other three gauges are rather low impedance(resistance)so read full sweep at approx 3v... I have a semi working mockup on the bench using the resistor from the cluster in series with the gauge(mine reads 23.1 ohm, can be seen in picts with red clip leads attached) and a 6.8 ohm shunt across the meter... Main problem is there is quite a bit of current drawn so resistor gets rather warm... What's needed is a variable regulator circuit that will reduce the output to approx 20% of input, gotta work on that... Of course the gauge being a bi-metal type, is slow as January molasses to respond but does work... Quote Selected
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