wiring an ammeter

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seattle##gs

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I am making a new wiring harness for a 1971 Commando using the headlight with an ammeter. I have made many wiring harnesses before but none with an ammeter, I greatly simplify them and they work well. However, I am doing this for a friend and he wants the ammeter. Here is a tentative routing, is this OK? I usually wire the podtronics direct to the battery, not so here.

BATTERY (NEG) (brown-blue wire)----FUSE-----KEY SWITCH-----AMMETER (neg side)----dead ends.

PODTRONICS (NEG) (black wire)----AMMETER (+ side)-----with a jumper to the headlight toggle switch

QUESTIONS: How does the ammeter read charge and discharge in this configuration? will or won't?

If the fuse blows while the bike is running, will it stay running from the alternator? Will the alternator be protected by the fuse on the
battery?
 
Think of your ammeter as an inline gauge, it is wired like a fuse.

One side goes to the battery, and the other side feeds all the consumers like lights and coil.
 
Install it for the looks, but don't count on it telling you much at all. If you really want to monitor your battery level install one of these, fits nicely in the existing headlamp warning light openings.

wiring an ammeter

http://www.ebay.ca/itm/12v-LED-Battery- ... 2c54cd0669
 
Thanks...I still don't understand how it reads charge and discharge but I will wire it as stated.
I know the stock Lucas ammeters are dicey at best
 
This is a quick drawing of how to wire the ammeter and Podtronics voltage regulator on a Norton Commando. You'll note that there is a wire that would go to a horn relay. Instead of a relay, you can wire it directly to the horn switch however, both your horn and your high beam flash would be hot at all times. The reason why your horn would be hooked up between the battery and the ammeter is so that the ammeter won't slam to a full swing deflection whenever you activate the horn. Also the wire coming off the ammeter to the headlight relays is purely optional - up to you.

The one fuse is all you really need however, you can add fuses for other circuits.


wiring an ammeter



I wired an ammeter on my 1974 Norton Commando using a miliammeter and a shunt wire. Also I wired my bike negative ground which you might want to consider at this stage of the game in case you want to wire LED's or other electronic components.

I hope this is of some help.

Peter Joe
 
seattle##gs said:
Thanks...I still don't understand how it reads charge and discharge but I will wire it as stated.
I know the stock Lucas ammeters are dicey at best
Click to expand...

Wire the ammeter as PeterJoe shows in his diagram.

As such, the ammeter registers the current that goes INTO (charge) or LEAVES (discharge) the battery. If the Podtronics is doing its job with the engine running at sufficient RPM, no current will leave the battery, and the ammeter will show the current the Podtronics is delivering to the battery. The current the Podtronics is delivering to the lights and ignition will not pass thru the ammeter and does not register on the meter. When the engine is shut down and the lights are on, the battery will discharge and register on the ammeter. The horn will not register on the ammeter.

Hope this clears it up for you.

Slick
 
Thanx Slick for helping me make sense of the current load bias choices. I am glad some folks go to such lengths for such little function but ah so satisfying to know they succeed. Ammeter is cute vintage touch to me so I put back in Trixie Combat but decorative only as did not want the extra wire resistance taking current form slow speed use so try to stay mostly in the green zone of LED meter creeping in at night via LED replacing the key left on assimulator indicator lamp. Pre-peel had 13 leaks when I got her and 14 after wards d/t trying to fill ammeter with oil and sealant failed.
 
seattle##gs said:
Thanks...I still don't understand how it reads charge and discharge but I will wire it as stated.
I know the stock Lucas ammeters are dicey at best
Click to expand...

a dicey ammmeter can shut down your whole bike if it is defective as was the case with me. I installed a brand new unit that was faulty and would cause the bike to die every 20 minutes and not start again for 5 minutes or so until it cooled down. Because the whole power system is routed through it you're depending on 1 component. I replaced mine with a miniature clock and run a volt meter on my handle bar mount.
 
zotz said:
seattle##gs said:
Thanks...I still don't understand how it reads charge and discharge but I will wire it as stated.
I know the stock Lucas ammeters are dicey at best
Click to expand...

a dicey ammmeter can shut down your whole bike if it is defective as was the case with me. I installed a brand new unit that was faulty and would cause the bike to die every 20 minutes and not start again for 5 minutes or so until it cooled down. Because the whole power system is routed through it you're depending on 1 component. I replaced mine with a miniature clock and run a volt meter on my handle bar mount.
Click to expand...

Yes, an open circuit fault in the ammeter isolates the battery. If vibration catches the ammeter coil the right way, the thick copper coil can break, causing open circuit.

You can prevent this fault by bridging the ammeter terminals with a piece of cable. The ammeter will still work, but with a reduced reading.
 
This thread has woken up a question I have had for some time: The solid state charging system has some level of saprophytic loss due to the back leakage of the diodes in the reg/rec. So, should it be wired through the master switch (key switch) such that it is disconnected from the battery when the motorcycle is turned off?

My gut says yes, but with a battery tender and weekly use, my experience say no; perfection may be at hand? I'd welcome your opinions.
 
RoadScholar said:
This thread has woken up a question I have had for some time: The solid state charging system has some level of saprophytic loss due to the back leakage of the diodes in the reg/rec. So, should it be wired through the master switch (key switch) such that it is disconnected from the battery when the motorcycle is turned off?

My gut says yes, but with a battery tender and weekly use, my experience say no; perfection may be at hand? I'd welcome your opinions.
Click to expand...

Use a multimeter to measure the leakage.

If it's microamperes, don't worry about it.
 
RoadScholar said:
This thread has woken up a question I have had for some time: The solid state charging system has some level of saprophytic loss due to the back leakage of the diodes in the reg/rec. So, should it be wired through the master switch (key switch) such that it is disconnected from the battery when the motorcycle is turned off?
Click to expand...

If you hook your voltage regulator the way you suggested the alternator may keep your engine running even after the ignition is switched off. If it wasn't for that reason alone it would make sense to hook the voltage regulator on the other side of the ignition switch.

Peter Joe
 
Maybe in ideal text book world the 12 v electron pressure on solid state devices should not ever break down resistance over time but its a factor of failure in modern cycles known to fry their rect/reg in 20K mile range like my SuVee did so had to source a more robust version. Mine did not fail from hi current flows as its rated to run radiator fan on hi beam with brake light and signals on which I never ever had happen at once. Key off should isolate everything from one side of battery then no voltage to resist 24/7/365.
 
I changed my ammeter today but didn't take notice on the color of wires that I changed. I wired it my self years ago so I forget how I added it to my harness. I drilled my headlight shell and placed it dead center above the light switch in place of the middle light. The original ammeter worked for 20 years, but stopped indicating charge direction this season, although my bike still ran fine with a broken ammeter and I tested the battery numerous times to make sure it was still being charged.... It was fine.

The new ammeter shows exactly at what RPM's my charging system overcomes the drain put on the system by the lights I have on. During the day, I just run a dim headlight mounted running light rather than my headlight. My system charges positively at 2200 rpms with the dim light on, and charges positively at about 2500 with the headlight on.. At 4000 RPM it's charging strongly and I imagine my zeiner diode is working overtime...

I could open the headlight shell and see which colored wires are connected where if you need that info...
 
PeterJoe said:
RoadScholar said:
This thread has woken up a question I have had for some time: The solid state charging system has some level of saprophytic loss due to the back leakage of the diodes in the reg/rec. So, should it be wired through the master switch (key switch) such that it is disconnected from the battery when the motorcycle is turned off?
Click to expand...

If you hook your voltage regulator the way you suggested the alternator may keep your engine running even after the ignition is switched off. If it wasn't for that reason alone it would make sense to hook the voltage regulator on the other side of the ignition switch.

Peter Joe
Click to expand...

I do not wire the alternator output into the wiring harness, but to the battery directly so the alternator output is behind the switch with the battery; no current gets into the harness unless the key is switched on.

My question was aimed at soliciting opinions about the level of solid state leakage Triton Thrasher suggest that the level is micro amps; I tend to agree.
 
Might check your dim light visability durring day time couple hunder yard aways to maybe convince to switch to normal or better hi beam on instead. Its not the battery drain concerns me as micro amp on scale of loss to air moisture a or floor storage or comic ray ion channels but the diodes or transitors interfaces bearking down sooner, though do not hear but a few Podtronic or Tympanium failures and if lasts a decade so what. I would rather run battery a bit low on intervals of low rpm in traffic than full topped battery risk and if going that slow for a while anyway then no need of bright light til pace and distances increase to charge and coool.
 
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