Installed voltmeter, need opinion and why.

[earlfor]

I installed a digital voltmeter on the 1150 this evening. At rest, ignition off, the battery shows 12.8 volts. Ignition switched on, all lights off, engine not running, I read 12.65 volts. I am assuming wiring harness resistances and the coils and electronic ignition being powered up is causing the .15v drop. I expect that as normal. Now, start the bike and hold 2k rpm. Turn on the headlight and tailights/running lights. Voltage in the harness reads 12.6 which is acceptable.
Now, with the dash mounted voltmeter measuring harness voltage, I connect a 2nd multimeter directly to the battery. Voltage from the R/R is 14.5 which is also as it should be.
Harness voltage is 12.6

Now to the question. To my thinking, It may be preferable to have my dash mounted voltmeter reading charging voltage rather than system voltage since it is the charging system I want to monitor rather than the battery.

What say guys. LOL

Earl

 

[Boondocks]

I installed a digital voltmeter on the 1150 this evening. At rest, ignition off, the battery shows 12.8 volts. Ignition switched on, all lights off, engine not running, I read 12.65 volts. I am assuming wiring harness resistances and the coils and electronic ignition being powered up is causing the .15v drop. I expect that as normal. Now, start the bike and hold 2k rpm. Turn on the headlight and tailights/running lights. Voltage in the harness reads 12.6 which is acceptable.
Now, with the dash mounted voltmeter measuring harness voltage, I connect a 2nd multimeter directly to the battery. Voltage from the R/R is 14.5 which is also as it should be.
Harness voltage is 12.6

Now to the question. To my thinking, It may be preferable to have my dash mounted voltmeter reading charging voltage rather than system voltage since it is the charging system I want to monitor rather than the battery.

What say guys. LOL

Earl

When I wired mine, I debated whether to wire it locally to the closest available sources of hot wire and ground or to a source better able to ensure an accurate reading without excessive voltage drop. I chose the latter, and wired the always-on hot and ground wires of the voltmeter to the accessories output on the fuse box. While not a direct battery connection, it is close enough and fused for protection.

I am not sure of your distinction between charging voltage and system voltage. The charging voltage is best reflected in the battery voltage. Checking the voltage at a distant point through a wiring harness with voltage drops due to connections and current usage is not the best way to go in my opinion.

It would be interesting to see the difference in voltage if both voltmeters are connected to the battery and same ground. Even with digital voltmeters, they may sometimes vary up to .4 volt on a 12 volt DC measurement depending on the quality and accuracy of the meter.

I would suggest that you first hook up both meters to the battery and check for any differences. The voltmeter gauge we have is inexpensive and might not be expected to be super accurate. If there are voltage differences under the same conditions, you will be able to covert the readings to the reference without concern.

On my bike, the voltmeter is usually within .2 volt of the battery (checked with a reference meter), and sometimes spot on (depending on conditions).

 

[earlfor]

I have the dash voltage/temp/clock display plus two digital multimeters. I'm going to do a comparison between them tomorrow and get back to you on that one.

On my distinction between charging voltage and system voltage:
Regardless of how long you charge a battery, when you check its at rest voltage, it isnt going to read greater than about 13.2v. Charging at 14.5 volts cant result inthe battery holding 14.5v. My R/R is connected directly to battery. Consequently, a meter connected to my battery terminals will show the highest voltage level, which is what the R/R is putting out. I think with the bike running, lights, etc. on, and since the greatest voltage the battery can push is about 13, and since consumption will reduce voltage, its reasonable to expect to see something in the 12.5 to 12.8 range at the end of the harness. Any discrepancy in pressure between the R/R and the battery is converted to heat and lost.


Please continue. This is becoming most useful. Yeah, really.

Earl

I am not sure of your distinction between charging voltage and system voltage. The charging voltage is best reflected in the battery voltage. Checking the voltage at a distant point through a wiring harness with voltage drops due to connections and current usage is not the best way to go in my opinion.

It would be interesting to see the difference in voltage if both voltmeters are connected to the battery and same ground. Even with digital voltmeters, they may sometimes vary up to .4 volt on a 12 volt DC measurement depending on the quality and accuracy of the meter.

 

[duaneage]

I also have the clock/temperature/voltmeter apparatus and I see almost the same voltage at the ignition switch connector as the battery terminal has. I tied mine into the green connector for the ig switch.

Try this:

Place the red volmeter lead on the + terminal of the battery and the black voltmeter lead on the spot where you have the CTV meter wired in.

If it is nearly 0 then the CTV is not as accurate as the VOM. If you record a signifcant voltage you have resistance my friend and woulddo well to find it. There should be almost no resistance from the battery through the main fuse into the green connector for the ignition switch, it is a straigh shot.

I think you need a better ground for the CTV apparatus, check that next.I ground mine to the ground pin of the green ig switch connector as well as it measured almost 0 ohms resistance to the battery - termnal. I always measure my grounds back to source, I never assume something metal is grounded on a bike.

 

[earlfor]

Thanks. I'm going to do some more checking tomorrow. The first thing I'm going to do is check for discrepancies between meters. I think a lot of the problem not appearing to fit together numerically may be meter differences. We shall see. I'll letcha know.

If there's a worm in my apple, I'll find it. eheh

Earl

I also have the clock/temperature/voltmeter apparatus and I see almost the same voltage at the ignition switch connector as the battery terminal has. I tied mine into the green connector for the ig switch.

Try this:

Place the red volmeter lead on the + terminal of the battery and the black voltmeter lead on the spot where you have the CTV meter wired in.

If it is nearly 0 then the CTV is not as accurate as the VOM. If you record a signifcant voltage you have resistance my friend and woulddo well to find it. There should be almost no resistance from the battery through the main fuse into the green connector for the ignition switch, it is a straigh shot.

I think you need a better ground for the CTV apparatus, check that next.I ground mine to the ground pin of the green ig switch connector as well as it measured almost 0 ohms resistance to the battery - termnal. I always measure my grounds back to source, I never assume something metal is grounded on a bike.

 

[Boondocks]

On my distinction between charging voltage and system voltage:
Regardless of how long you charge a battery, when you check its at rest voltage, it isnt going to read greater than about 13.2v. Charging at 14.5 volts cant result inthe battery holding 14.5v. My R/R is connected directly to battery. Consequently, a meter connected to my battery terminals will show the highest voltage level, which is what the R/R is putting out. I think with the bike running, lights, etc. on, and since the greatest voltage the battery can push is about 13, and since consumption will reduce voltage, its reasonable to expect to see something in the 12.5 to 12.8 range at the end of the harness. Any discrepancy in pressure between the R/R and the battery is converted to heat and lost.

Even a reading of 13.2V from a battery is indicative of a surface charge, which will diminish and stabilize 4-8 hours later at about 12.6V-12.8V depending on the type of battery.

It isn't a question of a battery "holding" 14.5V. If that much voltage is present at the battery, it is obviously being supplemented by the R/R (or a battery charger). But in either case, this is the effective voltage being presented from the battery, whether it can retain it or not. It isn't the battery per se "pushing" the voltage, but the combination of the battery and the charging source. This is why a bad R/R can cause blown bulbs, etc.. If the battery under charge could never put out more than 13.2 volts, bulbs wouldn't burn out from overvoltage. Sylvania specs the rated life of their halogen bulbs at 14V.

I agree with duaneage that you may have a ground problem, or a voltage drop on the hot side which makes it unfavorable for use. This is why I bypassed the wiring harness, to prevent this type of problem. Sort of like eliminating the "headlight switch" circuit from the third stator wire.

 

[earlfor]

The 1150 has been running flawlessly for a long time and other than perfunctory checks of obvious things, I have to admit, I havent been through it in a while.
It still is running perfect and starts within 1/2 second even if left untouched for a week. What started out as a simple question of what might be the best way to hook up my new clock/voltmeter has now changed my appraisal of the situation. I will do a thorough examination of the the electrical system starting tomorrow. Thanks to you guys, I'm getting a bad feeling. Funny thing is, I really do thank you. I prefer fixing things BEFORE they blow up.

Earl

I agree with duaneage that you may have a ground problem, or a voltage drop on the hot side which makes it unfavorable for use. This is why I bypassed the wiring harness, to prevent this type of problem. Sort of like eliminating the "headlight switch" circuit from the third stator wire.

 

[focus frenzy]

these bikes don't have the most efficient wiring system where voltage drop is concerned, take the headlight for example.

power comes from the battery, travels through the main fuse all the way up to the ignition switch, then returns back to the fuse box and through the lighting fuse then back up to the dimmer switch, back down to the frame then to the headlight.

I was seeing a healthy voltage drop on all systems

I rewired my G so that now power comes from the battery, goes through a master fuse and master ignition relay (generic 30 amp automotive relay) mounted next to the fuse box, through fuse box up to another relay wired to control the switch between low and high beam, then to the headlight.

the dimmer switch just controls energizing the headlight relay that switches the high beam on, you can rip the left switch pod off my bike and the headlight will still work on low beam.

 

[earlfor]

I found the problem. The ignition switch is dropping voltage. Power in is the same as battery voltage. Power out is as much as .5v lower depending on whether I rotate the switch back and forth and jiggle it. LOL Not good. I ordered a new switch. Should have it in a couple days. Bypassing the switch with jumpers, voltage stays the same in the harness. I'll take some more readings when I get the new switch installed.....see what kind of drop IT has.

Earl

 

[duaneage]

See??

Not only did the Clock-voltmeter-temp device not lie to you it found a potential problem waiting to strand you on route 27 at night in the rain.

When I drag my sleeping 650G from it's hibernation shed this month I go over all the electrical connections and use a volt meter to check the voltage at the rear lights, the coils, and across the important stuff like the ignition modules. takes me about 15 minutes and I don't have any problems. I use the testing technique I described.

 

[earlfor]

Hey, I'm not complaining. LOL Once I had the tank, seat, side panels and headlight removed, it took about 15 mins to isolate the problem. Time well spent. heh

Earl

See??

Not only did the Clock-voltmeter-temp device not lie to you it found a potential problem waiting to strand you on route 27 at night in the rain.

When I drag my sleeping 650G from it's hibernation shed this month I go over all the electrical connections and use a volt meter to check the voltage at the rear lights, the coils, and across the important stuff like the ignition modules. takes me about 15 minutes and I don't have any problems. I use the testing technique I described.

 

[tfb]

Now you've got me wondering guys...

I too noticed that my voltmeter read lower when wired in up at the ignition end of the loom, than back at the battery. So I wired up my voltmeter directly to the battery using a relay and an in-line fuse as close as practical to the +ive battery terminal.

But, time to check my ignition switch!

Cheers,
Mike.

 

[beby99]

Cool....I knew there was a reason I did'nt install mine yet. Just waiting for
you guys to find the faults. :-D