| nighthawk 550 electrical problem [message #455083] |
Thu, 29 September 2005 22:45 |
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Mark Olson Wrote:
> krusty kritter kriyamanna [at] aol.com wrote:-
>
> Mark Olson wrote:
> -
> This is a voltage regulator with a voltage sense line (a Kelvin
> connection for my EE friends)- my GL1200A had this exact problem.
> After cleaning all the connectors involved, the voltage drop was
> still larger than I liked, so I simply wired the regulator's sense
> line directly (thru a fuse) to the battery positive. I was worried
> that the regulator might drain current through the sense line when
> the bike isn't running but if it does, it's down in the microamps.
> Now the battery voltage is forced exactly to what the regulator
> wants it to be. A bodge, I admit, but it worked fine for me.-
>
> It seems that all Honda is doing by using a remote sensing wire is
> saving about 1/100th of an amp current drain...-
>
> No- the worry about long-term current drain due to me moving the
> remote
> sense wire so that it isn't switched anymore, is a side issue.
>
> The remote sensing wire allows the regulator to monitor a particular
> node in the charging circuit and adjust the regulator's output so that
> the monitored node is forced to the desired voltage. In this case,
> the positive battery terminal _should_ have been the node of interest,
> but Honda in their infinite wisdom decided to force the +12V bus on
> the switched side of the ignition switch to a voltage appropriate for
> battery charging.
>
> This wouldn't be a problem in a brand new bike with nice clean and
> springy
> BeCu connectors, but on an old bike with dirty and tired connectors
> there
> is significant voltage drop through the ignition switch and all the
> other
> connectors (and on a Gold Wing there are many) between the output of
> the
> regulator and the positive battery lead. So the switched side of the
> ignition switch is at a voltage appropriate for charging the battery,
> lets say ~14.5V, yet the battery itself is seeing somewhere between
> 0.5
> and 1V _MORE_ than that, so the battery eventually gets cooked.
>
> You would actually be better off without the sense lead in this case,
> since the voltage drop on the big wires between the regulator output
> and
> the positive battery lead is far less than the voltage drop through
> the
> less robust wiring routed through the ignition switch.
>
> --
> Mark '01 SV650S '99 EX250-F13 '86 GL1200A '81 CM400T
Mark,
My Clymer manual should be here tomorrow. Once I look at the
section referring to the rectifier I will try your fix. In the
meantime, one of my electrician friends at work asked if I had checked
the coils yet. He said that it is possible if the resistance is too
high on them they could be failing which would also impede the charging
capacity of the bike's charging system. Have you ever heard anything
like this before. It sure sound relevant due to how poorly the bike
runs until it runs for a minute. It does not seem that it is an issue
of warming up because even after it begins to run well it can go back
at any moment to running poorly.
--
jlpridge
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| Re: nighthawk 550 electrical problem [message #455086 ] |
Fri, 30 September 2005 00:23 |
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jlpridge wrote:
> My Clymer manual should be here tomorrow. Once I look at the
> section referring to the rectifier I will try your fix. In the
> meantime, one of my electrician friends at work asked if I had checked
> the coils yet. He said that it is possible if the resistance is too
> high on them they could be failing which would also impede the charging
> capacity of the bike's charging system. Have you ever heard anything
> like this before. It sure sound relevant due to how poorly the bike
> runs until it runs for a minute. It does not seem that it is an issue
> of warming up because even after it begins to run well it can go back
> at any moment to running poorly.
I assume when you are talking about 'the coils' you mean the alternator
stator, not the ignition coils, just to be clear. No one refers to the
coils of wire in an alternator as 'the coils', they call them 'stator
windings' or simply 'the stator'.
It's possible your stator windings are shorted or open, but most people
don't know how critical fractions of an Ohm are when diagnosing them,
and how to correctly perform such low-resistance measurements. The
cheapie digital meters you buy for $10 may have 1-Ohm resolution on their
lowest resistance scale which makes them useless for checking for shorts.
Have you done an open circuit AC voltage check of the three wires coming
out of the stator? That usually tells you whether your charging system has
the potential (no pun intended) of working. If that checks out, then I'd
proceed to testing the rectifier diodes in the reg/rect and the rectifier
itself as a component, if possible.
The fault finding chart at
http://www.electrosport.com/electrosport_fault_finding.html
(formerly electrexusa.com)
is really very good, and is worth following exactly as directed, even if
you have a service manual.
--
Mark '01 SV650S '99 EX250-F13 '86 GL1200A '81 CM400T
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| Re: nighthawk 550 electrical problem [message #455092 ] |
Fri, 30 September 2005 02:05 |
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jlpridge wrote:
> My Clymer manual should be here tomorrow. Once I look at the
> section referring to the rectifier I will try your fix.
I don't know if you understand the nature of Mark's solution to the
remote sensing wire problem or not. If the remote sensing wire is open
or has high resistance, the voltage regulating circuit in the rectifier
regulator won't work and the voltage will get too high.
That's which Mark moved his wire, he wanted to avoid burning up his
stator from HIGH voltage. Your problem so far seems to be LOW voltage.
Your stator could already be partially shorted out, but you need to do
the open circuit voltage test to see if it's putting out AC voltage at
5000 to 7000 RPM.
The rectifier regulator is a two part device which has the six diodes
that change AC from the stator into DC that the battery can use.
The voltage regulating circuit is a silicon control rectifier that
grounds out one phase of the stator when the voltage gets too high. The
silicon control rectifier is sometimes also called a "thyristor".
When the SCR grounds one phase of the stator, that cuts the AC outout
in half momentarily. The silicon control rectifier has enough built-in
resistance, when it conducts electricity to ground it just gets hot
without hurting itself.
The remote sensing wire simply sends voltage to a component called a
zener diode in the voltage regulating circuit of the rectifier
regulator. A zener diode is a kind of diode that doesn't conduct
electricity until the voltage reaches the desired level. Then the zener
diode conducts electicity to the gate of the silicon control rectifier,
telling it to
shunt the high voltage (around 15 to 16 volts) to ground.
That's why the rectifier regulator is also called a "shunt type
regulator".
It just wastes excess voltage into the frame of the motorbike.
> meantime, one of my electrician friends at work asked if I had checked
> the coils yet. He said that it is possible if the resistance is too
> high on them they could be failing which would also impede the charging
> capacity of the bike's charging system. Have you ever heard anything
> like this before. It sure sound relevant due to how poorly the bike
> runs until it runs for a minute. It does not seem that it is an issue
> of warming up because even after it begins to run well it can go back
> at any moment to running poorly.
You might have loose connectors on the ignition control module or on
the ignition coils themselves. If you want to see if you have enough
voltage to produce adequate sparks, install a fully charged battery,
remove the spark plugs and reinstall the plugs in the plastic
connectors on the end of the ignition wires and crank the engine over
while holding a spark plug about 1/4 of an inch away from the cylinder
head. If you get a bright blue spark that jumps 1/4 of an inch, you
have enough spark to rev up the engine to do your open circuit test.
If you get a weak white spark that won't jump 1/4 of an inch, or it's
orange or red, that's really weak and you'll need to figure out what
the problem is. An electronic ignition system either works or it
doesn't, the most likely problem for weak spark is dirty or loose
connectors.
If you don't have a weak spark, the most probable reason for bad
running is dirty idle mixture jets. I've described what to do about
that in this newsgroup about a bazillion times, so you can google that
information up.
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