1983 Honda Nighthawk 650 gets no power

Drove the bike yesterday and it did just fine, parked it and came back
and turned the key to find nothing lighting up or working. Tried the
starter button and got nothing. It is as if the bike is still turned in

the OFF position.


Checked all the fuses they were good, checked and charged the battery,
I do not know what else to do. This morning I turned the key and the
console lit up, headlight came on, and everything was how it was
supposed to be. Turned it off and then back on and it hesitated to
light up but did. Waited 30 min and tried again and again it decided to

not respond.


Checked battery and fuses again and they are all good.


What could the problem be?!?

 

Drove the bike yesterday and it did just fine, parked it and came back

The problem could be your battery..... just because the lights light up,
does not necessarily mean the battery is good.... it can be weak.. weak
enough not to do anything else... i would also check the ground wire to make
sure it isn't corroded.. in fact, check both cables from the battery
(wouldn't hurt)... if that doesn't help.. replace the battery.... you make
no mention as to how old it is....

Good Luck

Fwed

 

nothing lights up, battery registers good with volt meter. battery is <
6 months old.

 

nothing lights up, battery registers good with volt meter. battery is <

What does it register?? as in how many volts? also have you checked the
battery cables to make sure they are making proper connection? you sould at
least have lights when you turn the key....unless when you hit the kill
switch everything gets cut.... if that is the case, maybe its your kill
switch malfunctioning...I assume you have checked all the fuses with the ohm
meter too while they are out of the holder??

Fwed

 

battery is good, forget how many volts it had but it was within spec.
Checked all fuses with ohm meter. All of them were good.
I checked all cables and connections and they are all good, I filed and
sanded the ones that "looked" dirty.
No lights when I turn the key.
Did not think to check kill switch, going to check ignition switch and
kill switch with the volt meter tomorrow.

 

battery is good, forget how many volts it had but it was within spec.

Ok.. meanwhile, I will check the manual to see if I can find anything as
to why you have no lights....

Fwed

 

Checking the battery with a volt meter is only a partial test, battery can
show sufficient voltage and still be useless.
Check it with a hygrometer. This may help:
http://homepage.sunrise.ch/mysunrise/joerg.hau/mot/batt.html
I wasted almost a week looking for electrical gremlins because I tested a
battery with a voltmeter and it showed enough for me to think it was ok,
rechecked later for specfic gravity and found several dead cells.
PQ

 

Don't forget to measure wind speed with an anemometer, and record the
barometric pressure readings and send up weather balloons to
investigate winds in the upper atmosphere. Check your weather satellite
downlinks for
recent photographs of weather systems over the oceans. ;-)

Electrolyte specific gravity can be measured with a turkey
baster-looking device called a "hydrometer", but electrolyte specific
gravity and terminal voltage checks don't mean a damned thing when your
battery gets old and has sulfated plates. The only sure test of a
battery's capacity is a load test.

Charge up the battery until the voltage reads as high as it can get,
compare that apparent state of start with how high the float floats or
count the rising balls and flick the ball-type hydrometer until all the
little bubbles detach themselves from the balls, and you will have a
guesstimate of the state of battery capacity.

Then hook up a load tester, or a headlight bulb of known wattage across
the terminals and monitor the terminal voltage throughout the test.

If you hook a 60-watt headlight across the terminals, it should draw 5
amps at 12 volts. Check the test periodically, watching for the voltage
to drop below 12 volts. A fully charged 12 ampere hour battery should
keep a 60-watt high beam lit brightly for 2.4 hours without dropping
below 12 volts...

 

The lights are routed through the kill switch on that bike.


--
RCOS #7
2005 FJR1300AT
1992 GL1500 (sold)
1985 CB700SC
1984 XL500R (sold)
1979 SR500E
1971 CL175
1969 Schwinn Sting-Ray (totalled)

 

Ok... it looks like I can't find anything on your bike.... (i have
limited resources) but it any event... if your battery is in fact good...
then it sounds like you have a faulty ignition switch, or a faulty kill
switch (if headlights are wired thru this switch) or a main fuse.. make sure
yo uhave checked ALL of your fuses... this means take them out of the holder
and check with a volt meter to make sure there is continuity in them...(roll
the fuse as you do this to insure no break)... then check the fuse holder
for continuity.....

Good Luck..

Fwed

 

No, I'm not. On my CB700SC Nighthawk, the lights are routed through
both (starter and kill).

--
RCOS #7
2005 FJR1300AT
1992 GL1500 (sold)
1985 CB700SC
1984 XL500R (sold)
1979 SR500E
1971 CL175
1969 Schwinn Sting-Ray (totalled)

 

Correct, hydrometer.
Sorry-old fingers.
PQ

 

alright, i found the problem and it was that there was a short that had
melted plastic onto the contacts.

It is in the very front of the bike, I do not know what it is called
but it distributes the power ones the key is turned in the on position.

I have disconnected everything except the power into it and the switch
connection and when I turn the switch it still gets very very hot and
fast.

Any idea on what is causing the short?

 

replace the part that has the melted plastic and make sure when you replace
it the wiring is in good shape (not shorting out)

Fwed

 

the plastic that melted was the plastic cover and has nothing to do
with the wiring.

I am cleaning all the contacts and checking all the wires. I still am
at a loss as to what part of it is shorting out...

The weater is awesome... man I wish the bike was working properly....

 

A great place to start would be the wires coming from your ignition
switch.......since that is where you can't get any headlights..then move to
your wiring harness... These shorts can be tough to find...good luck

Fwed

 

Your ignition switch contacts make a high resistance connection and
that is melting the plastic? Been there twice, it wasn't a "short" at
all...

Most people confronted with electrical problems don't know the
difference between an "open" and a "short" and a "high resistance
connection" really confuses them, since the "high resistance" is so
LOW...

I will explain:

In an "open" circuit current doesn't flow through it at all, so the
wiring and parts can't even get hot from current flow...

In a "short" circuit, current doesn't go through the load you intended
it to go through. A common type of load is the headlight. If the
headlight was "shorted out" inside, it wouldn't light up, but enough
electricity would flow from the battery, bypassing the light, and back
to the battery, burning up the wiring, if a fuse didn't blow out
first...

I used the headlight as an example, because it's the biggest electrical
load on your bike that runs all the time. Your starter draws more
current, but not through the ignition switch...

If your bike really does have a "short" circuit from the switch and
back to the battery, just disconnect the battery and check the wiring
carefully with an ohmmeter from the wire that had power to it back to
ground, but be careful, you can make a real fool of your self with an
ohmmeter...

I know that because I spent about two hours tracing an elusive "short"
on an old T-28 trainer, and it turned out I was reading low resistance
to ground through the damned starter...

But, back to ignition switch problems. Why do they melt when they have
a high resistance connection? Switch contacts should have a *low
resistance* connection, it should measure 1/10th of an ohm or less. If
the contacts are worn and dirty, the resistance could get up as high as

1 ohm...

1 ohm is a high resistance contact for an ignition switch, because the
power dissipated (making HEAT) through a bad contact is equal to the
cuurent SQUARED times the resistance...

So, if a bad switch contact has to carry 10 amps to support all the
electrical load and the switch contact's resistance is 1 ohm,
10 X 10 X 1 = 100 watts. Now, you know you can't put your hand on a 100
watt light bulb when it's lit. 100 watts of heat inside the ignition
switch is going to melt that switch really quick...

I have had to replace two melted ignition switches...

 

that helps a lot. thanks.

Sounds like everything I am looking at.

The plastic is not melting in the ignition "switch" itself but it is
the "box" that sends power to everything once the switch is turned
"ON". The plastic melting is right in the area of the constant power
going to the switch and the power that comes from the switch once
turned "ON". Only gets hot when switch is turned to ON.

I guess a test would be to take a jumper and apply power to the box
bypassing the ignition switch and see if it still gets hot, or would
that not tell me anything?

I will take the connections apart and clean them real well and replace
any wire that does not check out.

 

I went to www.partsfish.com and found a 1983 CB650SC Nighthawk.
It shows the ignition switch on the "handlebar top bridge" drawing...

That damned ignition switch costs $125, but if it turns out you need an
ignition switch, you can propbably buy an aftermarket switch from an
online catalog place like www.denniskirk.com of from Chaparral
Racing...

I see the fuse box you're talking about on the "steering stem fuse"
drawing. It has some little plug-in fuses that you can get at any auto
parts stores. Check into the fuse box and see if the sockets where the
fuses are supposed to go are all corroded and green, or loose and
burned black...

If the fuse sockets are burned, you can clean the black oxidiation out
of the sockets with some stuff called Tarn-X. That's available in
drugstores and supermarkets for cleaning silverware. It's a mild acid
that you can soak electrical contacts in until they are clean. Then you
can flush the Tarn-X away with distilled water...

It is possible that the power wire feeding the fuse box is grounding
out and, if there isn't a fuse between the battery and the fuse box, a
bare wire touching the steering head might be what's getting hot, so
none of the fuses blow out because they are downstream of an actual
short circuit. There are about 4 fuses in that box.

If the fuse box is all melted and too badly corroded you might want to
look around some electronics store for an aftermarket fuse box to avoid
paying the Honda $tealer$hip a lot of money for that plastic box that's
worth maybe $5.00 at most. They would probably charge you $50.00 for
it, if they had one...

You may wind up replacing the fuse box with a few inline fuse holders,
but get the best ones you can, some of those cheapies are really
junk...

Yes, you could jumper around the fuse box, but be careful not to burn
out anything else in the wiring. If you could find a heavy duty inline
fuse holder and put a 25 or 30 amp fuse in it just for a test jumper,
the fuse would blow out before damaging anything else...

Try that Tarn-X stuff for burned looking connections. If the
connections have gotten that hot, the tin plating is probably gone, and
Tarn-X will clean the contacts down to the bare copper...