Installed a voltmeter

[gearhead13]

After having recurring problems with charging and starting, replaced my R&R with a shindengen mosfet one, and a new AGM battery. I bought an LCD voltmeter off of ebay :
http://www.ebay.ca/itm/New-7-5V-20V...532?pt=LH_DefaultDomain_0&hash=item231f5a5eac
and mounted it to my handlebars. Most of the time the volt readout is all over the place depending on rpm. Some kind of interference ? making it wonky. I wired the + to the positive line going from my relay mod to the coil. The negative was bolted to the coil mount. I thought the high voltage spark was causing it so I switched the ground to the engine. It didnt help. So, either the positive is being affected by the spark or the meter is wonky or just way too sensitive.? So where can I find a switched + source that shows full battery voltage besides my relay output?
EDIT: a thought that maybe I should connect the + wire to the battery and run it to see if the readout is steady....

 

[gearhead13]

If the readout of this thing is still wonky after directly wiring it, consider this a negative review of this type of voltmeter on ebay.
****es me off because of the time, effort and money spent on buying this thing, mounting and wiring it as well as all the troubleshooting I have done so far.

 

[chuck hahn]

Voltage goes up and down with relevance to the RPMs...if you disconnect the meter and use your multimeter directly to the battery and run up the RPMS youll see that it too flucuates up and down...which is normal.

 

[Agemax]

i have my volt meter connected into the orange wire from the ignition switch and the ground connected to a spare connector in the headlight bucket.
apart from the expected fluctuation with rising revs it reads steady

 

[gearhead13]

It doesnt just rise and fall with revs, its flip flops all over the place even showing a negative sign at times. Once and a while at certain times it shows ~14.2, so I know it works somewhat. Just some kind of interference, like vibration or spark voltage making it go crazy.

 

[Agemax]

i would connect it direct to the battery and try it. if it is still all over the place then it has to be a dodgy voltmeter

 

[barnbiketom]

Gearhead, that is EXACTLY the same one i got and it is from the SAME SELLER.

I connected mine several places but ended up running a wire back to the battery. I wasn't happy with a reading of 1/2 to 1 volt loss on the gs400 in the headlight area.. i just needed to know exactly what the bat was doing.

Mine flashes and flickers at idle but at slightly above idle (1300) it reads out just fine. I figure it is the 'less than perfectly square output" of the rect/reg confusing it.

however, riding down the road and around town.. it always displays correctly.

Idle.. not so well but it is still very useable.

if yours does the jumping all around all the time , contact him and i bet you will get a replacement.

 

[tom203]

i would connect it direct to the battery and try it. if it is still all over the place then it has to be a dodgy voltmeter

Yeah, some of these meters are crap out of box. But some meters don't have enough damping circuitry to show an "average" reading.Wiring to orange wire from key switch is a good spot- probably about 1/2 volt less than actual battery- good enough for me!

 

[spyug]

I have exactly the same issue but what do you expect when the dang thing was $2 shipped free from Shanghai? I actually bought a few of them and I think one out of 4 worked. I've had a lot better luck with good old 'Murcan made analog units.

Perhaps not as accurate as digital but good enough for government work I can tell if I'm charging and as long as it doesn't jump to 15v+ I know things are working.

Our local Aladdins Cave (Princess Auto, like Harbour Freight) has them on for $6 this week and I'm going to stop in this afternoon and pick up a couple. for that price you can't go wrong IMHO.

cheers,
spyug

 

[jpaul]

I have a different digital voltmeter, which I have wired to the battery. When I had my heated grips hooked up, I noticed that the voltage reading was unreadable when using the grips. The controller for the grips was designed to switch the grips on & off up to something like 20 times per second, depending on the setting you chose. It would be on 30%, 40%, 75%, or 100% of the time, depending on the setting. If you're hooking your voltmeter up to the coil circuit, you could see the voltmeter trying to read the voltage as it changes every time the coil fires the plugs.

Short version; hook it up to the battery.

 

[Agemax]

i bought this one......
http://www.ebay.co.uk/itm/261145140...eName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

ok, more expensive but from a UK seller so i got it fast, and it works great.
probably still made in japan or asia somewhere but at least with a UK seller it is easier for me if i had any issues with it.

 

[gearhead13]

Its been 6 months + or so since I bought the voltmeter, so I doubt about getting a replacement. I am now thinking that even running the + and - wires past or anywhere near the coils and HT leads would induce voltage that would confuse the meter. There must be some kind of filter that could be wired inline to the meter to help. I remember some car amplifiers that came with filters to run on the + side as a filter.

 

[spyug]

I very much doubt that you can do anything with these cheapos. I have tried wiring mine seven ways from Sunday and no improvement. Even wiring directly to the batery it jumps and twitches all over the place.

I think you'd be better off just junking it and going with something entirely different, unless you enjoy driving yourself crazy But, on the off chance you do get it to work please let us know.

Good luck with it.
spyug

 

[gearhead13]

I very much doubt that you can do anything with these cheapos. I have tried wiring mine seven ways from Sunday and no improvement. Even wiring directly to the batery it jumps and twitches all over the place.

I think you'd be better off just junking it and going with something entirely different, unless you enjoy driving yourself crazy But, on the off chance you do get it to work please let us know.

Good luck with it.
spyug

I had a look at the gauge you mentioned at Princess Auto. Might be the way to go. I'm not sure where or how I would mount it though. Might be a good excuse for a ride to go look at it closer.

 

[eil]

You could probably put an electrolytic capacitor in line with the voltmeter to smooth it out some. What size, I have no idea, it might be a trial-and-error thing anyway. Just make sure the cap is rated for 24v or higher and that you get the polarity right.

 

[Agemax]

here is a vid of my voltmeter, wired up in the headlight bucket. looks solid enough to me......

http://s188.photobucket.com/albums/z260/agemax/?action=view&current=100_1475_zpsf364d64a.mp4

 

[Guest]

Like eil said I would put the capacitor in parralel with the display. It should even out the readings.

 

[posplayr]

Attached is a simple device that will filter a lot of the noise. The biggest part of the noise is the negative going spikes when the R/R shuts off requiring the battery rush in to supply current.

The diode only lets current flow toward the meter. The capacitor is in parallel to the volt meter so it always has the same voltage as the meter.
When the input voltage drops below the voltage on the capacitor the capacitor supplies current to the meter minimizing the negative swings.

This will drop the measured voltage measured by the meter by about 0.7 volts so that might not be the best but better than a wacky display.

So using this to filter a (fuel or temp) meter reference voltage might be a better choice,

 

[Steve]

I have installed this one on a couple of our bikes with good results.

It's not waterproof, but on a bike with a widndhield and other protection, it's not as big a problem.

It's also nice to have time displayed, but two temps are obviously designed for cages.

The display's backlight has two color options, the orange one matches the GS lighting quite nicely.

 

[posplayr]

I have installed this one on a couple of our bikes with good results.

It's not waterproof, but on a bike with a widndhield and other protection, it's not as big a problem.

It's also nice to have time displayed, but two temps are obviously designed for cages.

The display's backlight has two color options, the orange one matches the GS lighting quite nicely.

I agree, a better meter should not bounce around as much.