Voltmeter installing ?

[Old Rider]

I have bought a cheep voltmeter to keep track of the alternator charging rate, but As usual when it comes to electrical stuff i have 10 thumbs .Where do i connect the cables ?? i had planned to just place them at the negative and positive battery connections ,but then it will drain battery. ?. or maybe it drains so little that it is nothing to worry about ? Or i can place a switch to
turn it off when bike is parked

[Old Rider]

I forgot to mention that i want to see the chargingvoltage while the bike is running, not only the voltage on battery .I tested it by connecting the wires directly on the battery and then it shows
the charging voltage when engine is running but not sure if that is possible if i just connect to the ignition wires and earth.
By the way i have a spare battery here i will connect the voltmeter to se how much it drains the battery over night...

[Waiex191]

We bought one for the Magna. Haven't installed it yet but had planned to put it on the headlight wires.

[red]

Old Rider,

You can have a fused voltage line, very neat and easy, with a Fuse Tap.  If space is tight around the fuses, you can use a Blade Tap on a fuse instead.  The Blade Tap should have an in-line fuse in the wire you connect.  The Blade Tap connector is a standard .25" male spade terminal (with the female spade terminal on the wire end).  Most bike fuses are switched by the ignition key.  If you guess wrong, just select a different fuse.  The extra drain on any fuse will not matter at all.

The Voltmeter draws very little current, but there is a draw.  A Fuse Tap lets you cut off the Voltmeter, when you turn off the ignition.  Any auto parts store should have Fuse Taps, just match to the size of fuse you have in the bike.  See pix.

[red]

Old Rider,

Here is a write-up on the correct use of a Fuse Tap, that insures fuse protection for the added wiring.  If you have an in-line fuse on the new wiring, just off the fuse connection, then you are good, period.  The second post got things backwards; that is rant not valid, so disregard.

https://www.fjrowners.com/threads/fuse-taps.151595/post-1269703
.

[ZOA NOM]

You need to connect the positive side to a SWITCHED 12v source if you want it off when you turn off the bike. Don't just pick any 12v fuse. The easy way is to use a light probe to check the source with the ignition on and off.

[Old Rider]

Thank you guys for good advices ! Good write up Red    I will see  if i can get  some fusetaps ,but in these coronatimes all stores except food stores are closed here i Oslo.
I have now just for testing connected the voltmeter to a spare motorcycle battery it read 12.9v when connected and still after about 2 hours reads 12.9v
Now its time for a beer happy Easter to all !

[Pat Conlon]

12.9v on a battery at rest shows a fully charged battery:

Open Circuit Voltage .................... State of Charge

12.80 volts or greater....................... 100%

12.60 volts ..................................... 75%

12.30 volts ..................................... 50%

12.00 volts ..................................... 25%

11.80 volts ...................................... 0%     

[red]

You need to connect the positive side to a SWITCHED 12v source if you want it off when you turn off the bike. Don't just pick any 12v fuse. The easy way is to use a light probe to check the source with the ignition on and off.

ZOA NOM,

You are correct.  Most fuses are switched by the ignition key, but a few may not be.  Checking the empty fuse socket, at each end, can be done with a test light connected to any good ground.  Pick a fuse that is is switched by the ignition key.  The extra load of a Voltmeter is so small, it will be inconsequential to that circuit when running.  The black lead of the Voltmeter can be connected to any good ground, but the closer it is (electrically) to the battery ground, the more accurate the readings will be, as a result.

[Waiex191]

Red,
Thanks, that is awesome.  I didn't know fuse taps existed.

[red]

Red,
Thanks, that is awesome.  I didn't know fuse taps existed.

Waiex191,

I made it a web page article, for easy future access:

https://user.xmission.com/~red/Fuse%20Taps.htm

Just bookmark the link.   
.

[Old Rider]

Have not installed voltmeter in the bike yet and had trouble getting the fusetap ,so instead i will just install like in the drawing . I'm feeling silly asking about this simple
wire diagram i made but have had some bad experiences with electrical stuff in the past and don't want the bike to catch on fire  .
I did test how much the voltmeter drains the battery and the battery voltage only dropped from 12.9v to 12.8v in about 48 hours and when i connected it again later the
battery was 12.9v again . So the voltmeter can be on when bike is parked without any big draining ,but i will install with a on/off rocker switch

[ribbert]

..... have had some bad experiences with electrical stuff in the past and don't want the bike to catch on fire  .

..... i will install with a on/off rocker switch.

You could always wire it in such a way that it only works when the ignition is on, this would be much tidier, and long term, a better job than a manual switch. Plenty of folks here happy to provide how-to instructions for that.

If everything on the bike is correctly fuse protected, it's not going to go up in flames.

Noel

[aviationfred]

You can splice into any of the Light Brown wires that run throughout the wire harness. When you turn the ignition switch on (Key switch), your volt meter will show what the battery voltage is. Once started and the RPM's get above 1500rpm, the voltage will rise to the optimal reading of 14.3 to 14.7 volts. Watch the volt meter in the video.

https://youtu.be/llC1HZisOBo



Fred

[Old Rider]

Noel & Fred  (and everybody else) thanks for your  advices ! but after posting this morning i rushed out to mount it    very nice gauges you got there Fred and much easier to see in the daylight than the
voltmeter i installed today.
Anyway everything worked and no wires started to glow red  
here is the final and fresh from the oven update .