Topic: In-dash voltmeter reading seems high (Read 8967 times)

110tHunDer · « **on:** March 14, 2004, 07:41:15 AM »

What does your bike's volt meter read at cruising speed? Mine sits at about 15 volts which seems high to me. Just wanted to see what you guys are experiencing before deciding whether or not to have the dealer take a look. Thanks!

JCZ · « **Reply #1 on:** March 14, 2004, 11:03:49 AM »

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What does your bike's volt meter read at cruising speed?

110tHunDer · « **Reply #2 on:** March 14, 2004, 12:33:56 PM »

JCZ, thanks, I feel better already. They probably held the voltmeter to the same accuracy standard as the air temp gauge [smiley=laugh.gif] !!!

Bikrtrsh · « **Reply #3 on:** March 14, 2004, 03:49:41 PM »

I don't know for a fact but I think the altenator is supposed to charge at 15 to 16 volts. Anything less than 13 to 14 and I'd be looking for a new battery or altenator. At any rate, I don't think it's anything to be overly concerned about.

I do know this, at HD every bike is roll tested. If the voltage is less than 14 it fails the test. Everything is double checked before the bike ships, I'd say that just the fact that all of us are showing basically the same voltage output that we're OK. It seems unlikely that every SEEG would escape with a faulty regulator or altenator.

Just my humble opinion tho,
Mark

JCZ · « **Reply #4 on:** March 14, 2004, 09:04:48 PM »

Just read my owners manuel and the charging rate max should not exceed 14.5. However, my guess is that these guages are wrong. I'd put a volt meter on it but I'm already scheduled for service Wed. (and I'm in the bay area Monday and Tuesday) so I'll just have them check it.

Baranca · « **Reply #5 on:** March 15, 2004, 08:22:37 AM »

Mine sits right at 15 also. Guess gauge is way off also and of course temp gauge is ridiculous. That's 3 ???outa 4!

WFP · « **Reply #6 on:** March 15, 2004, 08:35:35 AM »

I would also agree that mine reads to the high side...however, it's hard to tell since I feel the small guages are angled for some who's eyes are a little lower than mine...

Temp guage...yeah right...more like a wish guage. And the Fuel guage is the least accurate of all the bikes I've owned. At the first fillup I put in 4.45 gals and the low fuel light had never been on. Seems you can go 100 miles before it drops below 3/4 then it plummets

JCZ · « **Reply #7 on:** March 15, 2004, 09:34:09 AM »

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I would also agree that mine reads to the high side...however, it's hard to tell since I feel the small guages are angled for some who's eyes are a little lower than mine...

Temp guage...yeah right...more like a wish guage.

ggraves427 · « **Reply #8 on:** March 15, 2004, 02:24:06 PM »

Mine also reads around 15 volts, I am going to wait 23 months and then check it again.

Doc · « **Reply #9 on:** March 15, 2004, 03:15:16 PM »

Is anyone's not reading high?? Mine is reading high also.

Cabo · « **Reply #10 on:** March 15, 2004, 06:43:01 PM »

yes..15amps on mine

WFP · « **Reply #11 on:** March 15, 2004, 06:59:43 PM »

OK, I took a ride after work since there will be anywhere from 1" to 10" of snow in the next 24 hours

First, the guage itself is non-linear between the longer arc from 12-14V there are 3 dots, what could be considered 12.5, 13, 13.5. Between, 14 and 16V, a shorter arc, there are only 2 dots, which could be considered 14.67 and 15.3.

On my ride today, it was steady on the first dot after 14, or what would be 14.67V

That all assumes proper calibration of the guage...

mr_magoo · « **Reply #12 on:** March 16, 2004, 08:29:29 AM »

Glad you guys will have it all figured out by the time mine gets here. JCZ howd you get 5.2 gallons in a 5 gallon tank. [smiley=confused5.gif]

Kingsalmon · « **Reply #13 on:** March 16, 2004, 10:28:50 AM »

My volt gauge reads really high as well. I don't have exact numbers but, I know its up there.
I still haven't figured the gas gauge out yet. The low fuel lite came on an I rode about 10 miles and put in 4.8 gallons. My Ultra is correct, I have a gallon left when the lite comes on. BTW the lite on the SEEG comes on at 142 miles into a tank and my Ultra lite comes on about 160 miles in.

JCZ · « **Reply #14 on:** March 16, 2004, 07:08:52 PM »

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Glad you guys will have it all figured out by the time mine gets here.

Kingsalmon · « **Reply #15 on:** March 16, 2004, 07:15:32 PM »

We all know why we get less gas mileage. It has to do with the right hand and wrist

JCZ · « **Reply #16 on:** March 20, 2004, 09:56:26 PM »

The dealership put a volt meter on my bike, when it was being dynoed and it does run at 15 volts when it's under way. They told me it's nothing to worry about but I didn't stop there. I've sent an email to the factory. I'll post, as soon as I get a legitimate response.

SixtySeven · « **Reply #17 on:** March 20, 2004, 11:08:29 PM »

Mine was just shy of the 16 mark today. I am also concerned so look forward to the response. At that voltage it won't harm the battery (actually helps charging), but not sure what else on the bike might be sensitive to a high input or supply voltage.

110tHunDer · « **Reply #18 on:** March 21, 2004, 07:26:25 AM »

My thoughts exactly. I wonder if this has anything to do with the fact that I've already had to replace both of the front turn signal bulbs because the low-wattage filament (the one that stays on all the time) had burnt out/? [smiley=confused5.gif]

JCZ · « **Reply #19 on:** March 21, 2004, 10:19:12 AM »

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Mine was just shy of the 16 mark today. I am also concerned so look forward to the response. At that voltage it won't harm the battery (actually helps charging), but not sure what else on the bike might be sensitive to a high input or supply voltage.

I think all of you guys should have the dealership put a meter on it, under load, with the bike running at 3,200 rpm range......till we get an official word on this. Also, anybody else haveing problems with blown bulbs? Please report here.

I got an "unofficial" word back this morning already. He said that "personally" he didn't think that 15 volts was anything to worry about but that he'll get the "official" word this week from the guys working on the touring bikes in the electrical dept.

starvin · « **Reply #20 on:** March 21, 2004, 12:02:38 PM »

I was playing around with the data i recorded with my race tuner and quess what it also records the voltage, out of the 20 minutes of riding that i recorded my voltage never got above 13.8v what i don't know is what my gauge was reading, I never looked. I'll check the next time out. If it ever warms up. [smiley=furious.gif]

SixtySeven · « **Reply #21 on:** March 21, 2004, 10:12:33 PM »

JCZ, there are two things that could cause a bulb to go prematurely other than simply a weak bulb. Excessive power cycling and excessive voltage. Excessive voltage will cause a higher than rated current to flow through the filament overheating it and shortening its life. Typically, this is prevented by a series current limiting resistor, but don't know if our bikes have these. So, if the voltage is truly 15 to 16 volts with no current limiters, that could be a problem.

However, I do wonder how accurate these gauges are so I am going to put a meter on my bike tomorrow nite after work and will report the results here.

Kingsalmon · « **Reply #22 on:** March 22, 2004, 10:30:57 AM »

My volt meter reads about 15 all the time, it doesn't seem to change when I turn on any accessories, spot lites, heater on the seat, etc.
I have changed my left front running lite (turn signal) one time.

Bikrtrsh · « **Reply #23 on:** March 22, 2004, 12:20:22 PM »

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JCZ, there are two things that could cause a bulb to go prematurely other than simply a weak bulb. Excessive power cycling and excessive voltage. Excessive voltage will cause a higher than rated current to flow through the filament overheating it and shortening its life. Typically, this is prevented by a series current limiting resistor, but don't know if our bikes have these. So, if the voltage is truly 15 to 16 volts with no current limiters, that could be a problem.

However, I do wonder how accurate these gauges are so I am going to put a meter on my bike tomorrow nite after work and will report the results here.

Actually, the higher voltage will cause a lower current flow (Ohm's Law I=P/E) for example: a 100W light bulb at 120V pulls about .83 amps. The same 100W light bulb at 240V pulls about .42 amps. Any higher resistance would increase the amount of current thru the circuit and add a load to your battery and charging system (the same as adding more lights). If ya wanna limit the amount of current at each lamp, stick an in-line fuse in series with it.

Exceptionally high voltage will shorten the lifespan of a bulb due to excessive heat tho. Also the hotter the filament the more fragile it becomes. A sudden jolt or possibly even vibration could cause the filament to break. Excessive power cycling as 67 said will kill 'em sooner. Also a poor vacuum drawn on the lamp at manufacture will lead to premature failure. The less vacuum, the brighter the light output for the same wattage lamp and the hotter that filament will burn = less lamp lifespan.

The 2 most likely reasons for premature lamp failure is #1: a bad electrical connection (check your ground & make sure the lamp is seated properly in the lampholder) or #2: poor quality lamp manufacture. I know that GE is content with a 15% failure rate on brand new lamps, I'm sure their competition is in the same ballpark. Oh, and check that little or no moisture can get to your lamp. However my tail light on the wide glide worked fine completely submerged in rain water. The lens filled up full! LOL Never did burn the lamp out.

Automotive use lamps are generally made more durable and less susceptible to a little higher voltage and/or vibrations and sudden jolts. Now if ya start runnin 24 volts thru your lights they'll burn mighty bright ....... for a short time. You may wanna step the voltage down a bit or get 24V lamps!!! Oh, and a 24V ignition too. [smiley=smartass2.gif] Yeah I know ....... I just had to be a smartass huh?!?!?
hee hee hee <SORRY [smiley=laugh.gif]>

Mark

SixtySeven · « **Reply #24 on:** March 26, 2004, 11:17:12 PM »

Cool, this is going to be fun...a debate. The german physicist Georg Ohm's law more correctly is I = V * nAd/T. Where nAd is effectively the measure of free electrons in a wire segment and T is the time it takes for those electrons to move through the segment. Super simplifying this becomes basically I = V/R where R is the resistance of a DC circuit. This translates into the more common and well known form of Ohm's law: V = I * R.

An analogy when thinking of this is that V is like a water pump, R is like a valve, and I is like the water flowing through the pipe. For any given setting of the valve (R), the higher the water pump pressure (V) the more water will flow through the valve and the pipe in a given amount of time. Conversely, closing the valve somewhat (increasing its resistance) will decrease the amount of water flowing through the pipe.

So, for a fixed resistance in a simple DC circuit (which is what a light bulb is), the higher the voltage the more current and therefore the BRIGHTER the bulb. This is what you are seeing as Power. Power is therefore consumed by a circuit while voltage and current is conserved. The equation P = V*I is representative of that but is not Ohm's law. Bottom line is that you cannot control P directly, you must do so by adjusting V or I. You can control V by adjusting the battery (or regulator output) voltage or using a voltage divider circuit to control the voltage the bulb sees (this would apply more of a load to the battery which is why I didn't suggest it). You can control I by adjusting the resistance in SERIES with the load (bulb) in the circuit. When you select a bulb by wattage you are basically selecting between various internal resistances. A fuse has ZERO internal resistance by design so putting a fuse in line with something will only protect that circuit from going above the current value limited by the fuse. It will no lower the current flowing in the circuit. To test this theory put a resistor (it's more fun with a potentiometer) in series with a light bulb in a dc circuit. As you adjust it you will see the brightness of the bulb go up and down. By putting different value fuses in, you will see no change (unless the fuse value is too small and the current pops it).

The comments about a 120V 100wt bulb drawing half the current when 240V is applied is correct. However, it is for the following reason. You cannot take a bulb designed for 120V use and simply apply 240V to it or you will fry it. The effective Resistance of a 120V 100wt bulb is approx 145 ohms. Applying 120V volts to the bulb causes is to draw approx .83A. If you simply applied 240V to it you would now draw approx 1.6A which would surely blow it. A 240V 100wt bulb is designed to consume 100 wts and to accomplish this the internal resistance is approx 571 ohms. The point is that they're not the same two bulbs.

Also the comment about putting a resistor in SERIES (not PARALLEL) with the bulb supposedly drawing more current from the battery is completely wrong. If a resistor is put in series with the bulb, the resistor value will be effectively added to the resistance of the bulb increasing the overall resistance of the circuit therefore lowering the current for a fixed voltage (remember the correct ohms law V = I * R). If you put the resistor in parallel with the bulb, then it would cause the load on the circuit to be increased. This is because series resistances simply add but parallel resistances actually lower the effective resistance a circuit sees (to get the effective resistance you must invert the value of each resistance, add them all, and then reinvert them to get the new value).

Anyway, that's how I learned it when I got my electrical engineering degree, but that has been a few years...

BTW, I put a DVM on my bike tonite and at 3000rpm the gauge looked like 15V (halfway between the 14 and 16) while the meter was reading 14.3V. Given the comment about the gauge being logarithmic, that could make what I was seeing on the gauge closer to accurate. Also, I checked with someone and found that most automotive bulbs will handle at least 20V, so 15 or 16 probably wouldn't hurt them afterall...

Doc · « **Reply #25 on:** March 29, 2004, 09:45:12 AM »

Ummm.....what he said!

mr_magoo · « **Reply #26 on:** April 22, 2004, 08:35:06 AM »

JCZ did you ever here back on the volt meter. [smiley=confused5.gif]

JCZ · « **Reply #27 on:** April 22, 2004, 09:31:36 AM »

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JCZ did you ever here back on the volt meter.

JCZ · « **Reply #28 on:** April 23, 2004, 09:26:27 AM »

He's over seas right now. He still feels that it's not of any concern but that we could call HD customer service at (414) 343-4056.

He also mentioned that he hadn't heard anything about a chrome problem and will be checking on that when he gets back.

mr_magoo · « **Reply #29 on:** April 25, 2004, 08:57:01 AM »

Thanks for the update JCZ.

spydglide · « **Reply #30 on:** March 25, 2005, 07:26:38 AM »

In addition to blown turn-signal bulbs, I've had two running spots die (prematurely, I think). Maybe it's all related to the charging rate, don't know. I do know that the inside of my front turn signals has the appearance of too much 'heat'. [smiley=nixweiss.gif]

Author Topic: In-dash voltmeter reading seems high (Read 8967 times)

starvin