TOPIC:

My friend is stumped with his kz1000st. The main fuse(white wire) keeps blowing after running say 15 min. Hes got all the bodywork off and checking all the wires. If he unplugs the headlight, it doesn't get hot so i'm thinking thats the problem! Any ideas?

That's a little confusing since the headlight should have a separate fuse....but that aside, I had the same problem on my '78 Z1-R. I read on here that the terminals on both sides of the fuse should be cleaned up...oxidation is causing resistance. I used some steel wool on mine and it never blew another fuse again. It's worth a try....keep us updated.

Your friend should do this:

Cleaning Motorcycle Electrics

1. 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. It can be purchased at most Radio Shack Stores or any electronic supply places. Or use any plastic safe electrical contact cleaner(NOT WD-40 !).

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

3. 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.

4. 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.

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

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

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

8. 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.

9. 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.

10. 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.

11. 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!

12. 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, along with boating supply stores.

13. 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.

14. 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

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

16. If any battery cable feels ”Crunchy” when flexed, replace it as possible corrosion is inside the insulation. Inspect all heavy duty battery cables and the smaller wire terminations(Bullet Connectors), for failed crimps, and those used in the electrical connectors, as they can fail over time.

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

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

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

21. 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.

22. 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

79MKII wrote: That's a little confusing since the headlight should have a separate fuse....but that aside, I had the same problem on my '78 Z1-R. I read on here that the terminals on both sides of the fuse should be cleaned up...oxidation is causing resistance. I used some steel wool on mine and it never blew another fuse again. It's worth a try....keep us updated.

Mike, did it fuse still get hot? We did that first as I saw that here too. LOL. Motor doesn't need to run, just the key switch turned on with the headlight on and she'll get hot to touch.......take the headlight off and its fine.

What is the wattage on the headlight bulb? Stock is 55watt low beam and 60 watt for high beam.

Have you measured the fuse points yet?

Which fuse are you touching to check for hotness? Are you checking all of them or just one? There should be two fuses that feed the headlight. One is the main and the other is just for the headlight. The main feeds the headlight through that second fuse. There's a 20A, a 10A, and a 10A. The 20A will have a white wire to it. The 10A headlight fuse will have a blue wire coming off of it and the other will have a Red and Blue wire coming off of it. Both of the 10A fuses are fed by a Brown and White wire.
Why is this important? Because if you are mistaking the main with the headlight fuse, you will be looking in the wrong place for your gremlin.

You know too, sometimes it could actually be a short in the bulb itself. I had a shorted bulb that worked but blew fuses. It drove me crazy till I changed out the bulb. All of the wires will have corrosion on them. Clean the ends like MFolks said. The buttons, all of that stuff. Guarantee you this will help to make things run cooler.

MFolks wrote: What is the wattage on the headlight bulb? Stock is 55watt low beam and 60 watt for high beam.

Pretty sure is oem. Tried another bulb and did the same thing. Will check them to be sure they are 55/60.

Have you measured the fuse points yet?

How is that done?

DiamondSkyBlue1000 wrote: Which fuse are you touching to check for hotness? Are you checking all of them or just one? There should be two fuses that feed the headlight. One is the main and the other is just for the headlight. The main feeds the headlight through that second fuse. There's a 20A, a 10A, and a 10A. The 20A will have a white wire to it. The 10A headlight fuse will have a blue wire coming off of it and the other will have a Red and Blue wire coming off of it. Both of the 10A fuses are fed by a Brown and White wire.
Why is this important? Because if you are mistaking the main with the headlight fuse, you will be looking in the wrong place for your gremlin.

Its the main fuse which is white. Only that one is getting hot and blowing, others are fine. Does this sound like a bad ground?

I'm sure its a ground somewhere. Mfolks was the first thing with his checklist. I had a problem with my ignition. It was loose and shorting out fuses, also the starter switch the other day got wet from the rain and blew a fuse. All of the contact points after 30 years need cleaning or switches replaced if the stuff is bad. I hate electrical gremlins but what can you do?
Listen, make sure all that stuff is checked over cause if you blow a fuse in traffic on the highway you will be in deep without a paddle up that creek you don't want to be up. Happened to me but I had a feeling about the fuse and decided to switch to an outside lane in traffic and just as I did it blew.
If you take it to someone they will charge the dahmer price. Get a manual and one of those volt ohmeters and go to town checking the wires.

You can remove, clean and tighten the Negative(-) battery terminal, and the one going to the engine mounting bolt. Also any place you see a BLACK with YELLOW stripe wire, that's a ground too. Check the ring terminals(the kind with the hole that bolts go through) for tightness and corrosion. If in doubt, get a M6 X 1 tap and clean out the threads in the frame.