light problem - follow up
Posted: Sat Mar 19, 2011 8:59 am
Good morning Mark.
For testing for a problem like the fuse issue or most any other of that type the
way I suggested is the best way to do it, if you leave the negative lead on the
battery you are measuring voltage drop across the entire circuit. While you can
do it that way if you want to start adding all of the other slight voltage drops
together.... why complicate the process eh. Under load a bad connection =
resistance = voltage drop = heat, none of which is good unless you are trying to
heat something. As an example a voltage drop of a couple volts across a 400amp
600volt switch I worked on recently drove the temperature at the switch blades
close to 200*C, wire is rated in most cases for 90*C, on a system where the
supply from the power utility might be anywhere from 590-605 volts the only way
you can measure voltage drop and use it as a simple valid test is to measure
across individual components.
If you suspect you have a problem with in the area of a fuse check the area of
the fuse, since there should be no resistance there, powered up and with the
load of the headlight on the fuse there should be no voltage drop across the
fuse clips, if there is you have a potential problem which you have determined
is between the fuse clips.
You mention using continuity, in this case and many others it is not as valid a
test as voltage drop. If you were to measure resistance across the above
mentioned fuse clips with no voltage applied meaning there is no load on it I'm
sure it would test as close to 0 ohms as a perfect example, I would suspect you
would see signs of over heating before you found a resistance problem.
Troubleshooting a live circuit is much much simpler then relying on
resistance... as long as you don't take a $10.00 meter and open up a 600volt
panel. Continuity in my opinion and experience is best used looking for failed
fuses, broken wires or components where you are looking for a known resistance.
So to answer your questions:
TESTING? Are you sure you don't mean,
..........Nope...I meant what I wrote
FOR VOLTAGE DROP: Put Neg/black lead on Nev./ground and don't move it and then
test BOTH SIDES, With the Positive. (red) lead.
.........Only if you want to test the entire circuit and not an specific
component
NOTE: Do not move the ground or you may change the quality of your connection
and THINK you changed the Voltage.
........What I think you are missing here is you are looking for a voltage drop
from any specific point to ground, you are going to find it in this case because
it is well documented the wires in the lighting circuit are too small, even if
you oversize the wires there will still be measurable voltage drop by the time
you get to the headlight, save yourself the complication and test at the point
you have problems with first.
FOR CONTINUITY TEST: you test ACROSS the same line.
........same for voltage drop, you are measuring for potential difference
between 2 specific points...if you apply what you said above when you are doing
a continuity test you would leave the negative meter lead on the battery cable
so the quality of your connection didn't change and make you think you changed
the resistance
Have a great day.....Greg
________________________________
From: mark ward
To: DSN_KLR650@yahoogroups.com; cactus_reese
Sent: Sat, March 19, 2011 9:17:18 AM
Subject: Re: [DSN_KLR650] Re: Light Problem - Follow up
TESTING? Are you sure you don't mean,
FOR VOLTAGE DROP: Put Neg/black lead on Nev./ground and don't move it and then
test BOTH SIDES, With the Pos. (red) lead.
NOTE: Do not move the ground or you may change the quality of your connection
and THINK you changed the Voltage.
FOR CONTINUITY TEST: you test ACROSS the same line.
--- On Sat, 3/19/11, cactus_reese wrote: From: cactus_reese Subject: [DSN_KLR650] Re: Light Problem - Follow up To: DSN_KLR650@yahoogroups.com Date: Saturday, March 19, 2011, 6:43 AM That was exactly the problem, Greg. --- In DSN_KLR650@yahoogroups.com, Greg May wrote: > > Something I should have mentioned about the type of fuse to fuse holder failure > > I mentioned in my reply is that you can generally find this type of problem >even > > before it happens by checking for voltage drop across the suspect fuse. > Since the fuse is just a short piece of wire it should have virtually zero > voltage across it, if there is voltage dropped across the fuse it is beginning > to change from a fuse to an electric heater, unless address it will just get > worse To check this put your positive meter lead on the supply side fuse clip > and your negative meter lead on the load side fuse lead, this will not just > check the fuse but also the fuse to fuse clip connection....later.....Greg > > > > > ________________________________ > From: Greg May > To: cactus_reese ; DSN_KLR650@yahoogroups.com > Sent: Sun, March 13, 2011 10:54:13 AM > Subject: Re: [DSN_KLR650] Re: Light Problem - Follow up > > > Good morning Bryan > > Glad you found your problem and it turned out to be a simple issue. A couple > things that might save you future problems, most people seem to change the 10A > fuse for a 15A, the 10A apparently fails if the switch between hi and low hangs > > up so both are powered at the same time. The second thing I would look at if >you > > > still have the stock glass fuses. Because of the type of problem you had I > would check the clips the fuse fits in to ensure the fit is tight. If the fuse > > holder doesn't make good contact with the fuse, especially on the supply side >of > > > the fuse you can get enough heat to cause the solder that holds the fuse >element > > > to fail leaving you with a fuse that will actually appear good, then bad maybe > several times till it actually fails, usually at an inconvenient time of > course......Have a good day...Greg > > > > ________________________________ > From: cactus_reese > To: DSN_KLR650@yahoogroups.com > Sent: Sun, March 13, 2011 12:49:49 AM > Subject: [DSN_KLR650] Re: Light Problem - Follow up > > > Here is the resolution to my light problem. It was the 10A fuse after all. The > fuse was making an intermittent connection internally. It finally failed hard >so > > > it was easy to diagnose. The only things on the 10A fuse are the driving lights > > so, for everyone's benefit, when those go and nothing else, check that fuse. > -Bryan > > --- In DSN_KLR650@yahoogroups.com, "cactus_reese" wrote: > > > > I'm in Tucson. I was a regular a few years ago...then I became >irregular...but > > > >kept riding. 36K mile on my A12...at least 50% off-road. > > > > I'll try the good suggestion you guys provided. > > -BR > > > > --- In DSN_KLR650@yahoogroups.com, mark ward wrote: > > > > > > Hey Reese I could not find you on Our Map, Where are you?? > > > Mark (W. Mi.) > > > > > > > [Non-text portions of this message have been removed] > > > > > > > [Non-text portions of this message have been removed] > [Non-text portions of this message have been removed] [Non-text portions of this message have been removed]