TOPIC:

Hello all,

My name is James, I have a 76' kz900. I've had the bike for about 4 years and done some serious riding and a fair amount of work on it.

My latest problem is as follows:

My main fuse is blowing about 5-10 seconds after turning the ignition 'on'. The neutral light is dimmer than usual, and gets dimmer for the 5-10 seconds before the main fuse blows. The condition of the white, red/white wires involved with the main fuse was pretty bad, so I re-wired it with an in-line fuse and took it out of the fusebox. I thought that this may be my problem, that somewhere in there there was a short. No dice, when I tested it out it still exhibited the same symptoms.

Brand new battery, dyna-S ignition and coils were installed by me about 2 years ago.

I have jiggled/wiggled the visible wires in the harness and it doesn't seem to change anything. The rest of the wiring on the bike is stock and original.

I have not yet checked for a loose wire/solder joint in the ignition switch but I have a feeling that will be my next course of action.

Any of you kz electrical guys care to give advice or input?

Cleaning Motorcycle Electrics

Get some of the De-Oxit electrical contact cleaner and figure on spending a good day going from the front of the bike to the back. It’s a plastic safe cleaner/preservative. www.deoxit.com is their website. Or use any plastic safe electrical contact cleaner(NOT WD-40 !).

On the older Kawasaki's, a majority of electrical connectors are inside the headlight housing requiring removal of the headlight, then the fun begins.

Do one set of electrical connectors at a time to avoid mixing up what connects to where. Usually disconnecting, spraying with De-Oxit and reconnecting is about all you'll need.

However, when encountering the green crud of corrosion, a brass wire brush may be needed on the pins you can reach.
Some 400-600 grit wet and dry sandpaper strips rolled into a tube should reach the male and female pins in the more difficult to clean connectors.

Smoker’s pipe cleaners, cotton swabs and wooden toothpicks work as cleaning aids.

Really small electrical connectors may require the use of a welders tip cleaning tool assortment.

Most pins in the connectors are coated with a thin plating of tin, and others may be nothing more than copper or brass.

If moisture is added, the resulting corrosion lowers the voltage/current being carried causing dim lights, slow engine cranking, slow turn signal responce and lower input voltage to the ignition coils resulting in weak spark.

The left and right handlebar switch pods will need attention too as they have circuit functions like turn, horn, run/stop, and start. The older Kawasaki’s have reports of the soldered connections crumbling, if your bike has this problem, just ask, as I’ve got a repair procedure for this.

Usually a spritz or two with actuation of the switch is about all needed for these switches unless corrosion is detected and then careful disassembly is required.

The ignition switch may or may be not sealed to allow spraying the internal contacts. I urge caution if attempting to open this up as springs, and ball bearings may fly out never to be seen again!

If your bike has the older style glass tubed fuses, I suggest replacing them as vibration can cause internal failure. AGX is the type used, and most auto parts stores can get them for you.

Clean the fuse holder clips, looking for signs of overheating(discolored insulation, signs of melting).
I use metal polish on a cotton swab, followed by spraying another clean swab with the De-Oxit and then rubbing the inside of the fuse clip.

All battery cables must be clean and tight for maximum current transfer. Check the cables going from the Negative(-) battery terminal/post to the engine mounting bolt

Also the one going from the Positive(+) terminal to the starter solenoid and from there to the starter motor.

If any battery cable feels ”Crunchy” when flexed, replace it as possible corrosion is inside the insulation.

Each "Bullet Connector" will have to be sprayed to ensure good connectivity, especially the ones going to the energizing coil of the starter solenoid.

The alternator output “Bullet Connectors” are usually behind the engine sprocket cover and will need inspecting and cleaning too.

The turn signal light sockets will benefit from a spritz from the contact cleaner along with the tail light/brake light socket.

Some brake light switches can be sprayed on the actuating rod, with the spray running down inside to the electrical contacts, others may be sealed requiring replacement if the switch is intermittent in operation.

Some people put the Di-Electric Grease on cleaned terminations/connectors, I don’t, as I’ve read/heard it can cause problems when it gets hot, actually insulating the connections, so the choice is yours to use or not.

I think I've covered about all of the electrical systems on the bike.........

“I spent a weekend going through every electrical connection and switch on the bike with a little scotchbrite pad and DeOxit - what a difference! Everything was brighter, gauge backlights, indicator lights, turn signals, I was getting a nicer spark, it fired up quicker, etc. Well worth my time. WELL worth it! “

From a forum member at www.kzrider.com

And:

The Dreaded Shorting/Intermittent Electrical Problem!


Here is the most basic method I know(Taken from www.kzrider.com by member Patton)

1. Charge your battery and have it load tested if you can. The floating ball hydrometer can be used to check the specific gravity of the charged cells in the battery.

2. Disconnect the Black lead from the (-) Battery terminal... or Red from the (+) Battery terminal, it does not matter which one. Just 1, not both!

3. Connect one of the following test setups in series with the Battery terminal and lead:
3.1 A 12 V light bulb,
3.2 A 12 V test light,
3.3 A 12 V test buzzer or,
3.4 A 12 V horn... you get the idea.

4. With the Ignition Switch OFF, go through your harness and wiggle the wires while looking/listening for the test setup to go on/start buzzing.

5.With the Ignition Switch ON, repeat the test except this time the looking/listening for the test setup to go off/stop buzzing.

6. Be prepared to open the Ignition switch and check/test for solder joint failure and or circuit board micro breaks (don't ask how I know this ).

7. Be prepared to pull the wires out of the Head Light to test for failures at or near the grommet.

8. Be prepared to open the harness at or near the Steering Neck for failures. This is where wires tend to exhibit fatigue due to repetitive movement.

9. Be prepared to open the left and right switch gear to search for rust and or broken parts. CAUTION: watch out for flying springs, ball bearings and stuff. Do indoors on White sheet (again don't ask).

10. Be prepared to follow the heavy gauge wire from the Starter Solenoid (Relay) to the starter for bare wire exposure. Especially near bends and grommets.

11. If you can reproduce the fault symptom your are pretty much home free. Be prepare to find and repair/replace any internal wire breaks, insulation break downs, exposed wires, rubber grommet failures, etc. Often, shrink tubing will solve the problem temporarily until something better can be done.

The main wiring harness where it bends at the steering stem is known to be a problem. Every time you turn the bars, those wires are stressed and stretched. There could be a short somewhere in there, if you cannot more easily troubleshoot it.

Due to 5-10 second time delay....

Dis-connect coil and Dyna ignition (+12Vdc) for T-shooting.
Turn ignition on and see if fuse blows again...

Also insure coil mounting studs are not shorting to grounded frame...
Heat shrink or Nylon spacers...



I'm thinking coils as they warm up with current flow is causing the blown fuse...
But hey, that's just me....

Here is the latest:

Yesterday I went through a fair amount of the harness to look for damage/anywhere that could be shorting out. Something I moved or jiggled caused this short to stop happening, I'm not really sure what (which scares me) did it. I re-did a small portion of the wiring coming to/from the main fuse because it was in really bad shape, also put an in-line fuse holder in and got it out of the fuse box.

So whatever I jiggled and stopped the short now is causing the starter button to not work - no power there.

OMR, I like your idea, I'll check that out. The time-delay thing is what confused me really - in the past when I have had a massive short in a circuit on a bike, I turn the ignition switch on, and immediately the fuse blows...there is no 10 second delay.

Update:

I tested a few things today. Disconnected the hot line to the coil, It appears as though I am getting little to no voltage (<1 V dc) through that yellow/red wire when I turn the ignition switch on. Fuse is no longer blowing. Still no juice to starter. Im going to test the line from the starter button to see if I get voltage when hitting the switch.

Look inside the headlight housing for loose/corroded wires. I believe the red/yellow wire from the run/stop switch goes through a connector before going to the ignition coils.

also check inside the left and right handlebar switch pods for possible crumbled/failing solder joints. Here's a repair procedure if you discover them:


Repairing Motorcycle Soldered Connections

When repairing soldered wires on motorcycle switches or light bulbs sockets, have the following on hand:

1. A 25 Watt soldering iron or one that the wattage can be adjusted.

2. Rosin core solder.

3. Rosin flux or soldering paste (Never use solder or soldering paste designed for plumbing work, as it contains an acid that will corrode the electrical joint, ruining it).

4. 91% rubbing Alcohol, or 70%. The lower percentage will clean up flux residue, but not as good as the higher percentage stuff.

5. A cut down ½” paint brush, or acid brush for scrubbing the repaired solder joint.

6. Clean rags or paper towels

7. A damp sponge to keep the soldering iron tip clean.

8. Some “Solder Wick” a braided bare copper wire designed to collect heated excess solder, aiding in joint preperation, available at electronic supply stores.

9. Some wooden toothpicks.

10. Small Hemostats or clip on heatsinks.

A. Before soldering, “Tin” the soldering iron tip by plugging it in or turning the iron on, allowing it to get to operating temperature(2-3 minutes).

B. Unroll about 3” of solder from the roll of rosin core solder & then using a clean rag or paper towel moistened with Alcohol, wipe the unrolled solder, removing the finger print oils that will create a poor solder joint.

C. Apply a small amount of solder to the now heated soldering iron tip, wiping the excess off with the wet sponge, keeping a thin layer on the soldering iron.

D. The soldering iron is now ready for use, but before applying the heated tip to a wire, wipe the tip on the damp sponge, this removes any oxidized solder and makes for a much better connection.

E. If the joint to be repaired is grey in color or appears “Crumbled”, apply some rosin soldering paste or flux to the joint with a small toothpick of screwdriver, and then apply the soldering iron tip for a few seconds.

G. The fluxed joint should clean up, allowing for a better connection. If no luck, use the solder wick to remove all traces of the old solder by apply in it between the soldering iron tip and the bad joint.

H. Hemostats and clip on heatsinks will be used to prevent the wire insulation from burning, overheating & pulling away from the connection.

I. Apply a small amount of flux to the joint to be repaired & then a very short duration of heated soldering iron tip & solder(like a few seconds or so).

J. Clean off the repaired joint with the brush & rubbing Alcohol, the newly repaired joint should appear clean and bright, almost as if it were polished, with no voids or holes.

jenkrider wrote: Update:

I tested a few things today. Disconnected the hot line to the coil, It appears as though I am getting little to no voltage (<1 V dc) through that yellow/red wire when I turn the ignition switch on. Fuse is no longer blowing. Still no juice to starter. Im going to test the line from the starter button to see if I get voltage when hitting the switch.

Good Fortune!

Patton- Awesome diagram!

OMR - I think I may have discovered the original source for my main fuse blowing - As you suggested, I checked out my coil mounting job - A positive wire going to the left coil is right up against the mounting bolt, which was non-insulated!

I am currently checking out the condition of the right side handlebar switch assy. It seems as though Im getting power TO the engine kill switch, but regardless of position I am only getting <1 V out...

Back to the garage...

As a side note, I have been spending some time today cleaning connections as well. This is a pretty dirty bike. Lots of 30 year old road grease and oil everywhere...

For anyone interested, here is a little background: I have owned it 4 years, bought it from the original owner. Unfortunately, the fuse/shorting issue happened about a year ago right before I moved, hence I never had time to investigate the cause. Very, very unfortunately my beloved KZ has been sitting in the shed since I moved - right at one year. I finally have finished some of my other projects and now am getting back into working on this bike. In summer of 2009 I took the bike on a 2 week long 3500 mile trip with my girl, after that is when I upgraded to the dyna-S ignition (after points issues on the side of the road 1000 miles from home!) My knowledge of bikes in general and older Japanese 4's has multiplied since that trip and since getting this bike - so now I am going to do things the right way this time around! This bike used to be my daily driver and it really has been bothering me for a year to not have it running.

Thanks for the help and input guys!

SOLVED!

The lack of power to starter/coils/etc was tracked down using the wiring diagrams and Patton's diagram. It was in fact the engine kill switch - was getting juice to it and but not from it. Pulled it apart and the contacts were corroded and shitty - cleaning solved this problem.

Now I've got power

Now I have to re-mount the coil so that the mounting bolt isn't touching the hot wire to the coil. This is what was causing my short.

OMR, what is that stuff on your coil leads, some sort of insulating goop?

Here's one of several insulating options ---

When mounting Dyna coils on 1976 KZ900-B1 LTD, may wrap the stock mounting spacers with small nylon tie straps which serve to insulate the spacers from the heads of the screws used to attach the coil leads to the primary terminals. (See following pic.)



Good Fortune!