HELP!!!! HEADLIGHT Problem 2002 750 Katana

[Red Kat]

Hello All,

First let me say I am pretty well versed on the bike and wiring diagnostics so please read and see if you can help. I have a perfectly functioning 2002 750 Katana with one minor problem. Sometimes the headlight will go out on both low and high beams for no apparent reason. The running light up front and all other lights continue to function normally. The light on the dash for the high beam indicator also goes out when the headlight does but I assume this is normal when the headlight malfunctions.

I have checked the battery terminals and cleaned them and also all fuses inspected and found to be normal and am at a loss to know what's happening. I am thinking it might be the ignition switch but I wonder why the front running light is not going out too? The engine also runs perfectly so the ignition seems to be fine.

Any help would be much appreciated as I do not want to have to surrender the bike to the shop....please help.

PS I do not have a shop manual or complete wiring diagram but perhaps if you have one you could post the pertinent info!! Thanks!

[The CyberPoet]

Re: HELP!!!! HEADLIGHT Problem 2002 750 Katana

2002 750 Katana... Sometimes the headlight will go out on both low and high beams for no apparent reason. The running light up front and all other lights continue to function normally. The light on the dash for the high beam indicator also goes out when the headlight does

One of three rudimentary problems, probably the first one:
(A) Bad ground connection at the negative side of the bulb circuitry. This would kill both the indicator and the bulbs at the same time, as well as killing both bulbs in either position.
(B) Bad headlight selector switch (cracked solder or too much contamination). Try jumping it and see if it changes behavior.
(C) Power leads grounding before headlight, usually associated with either a worn spot in the insulation and/or higher-than-stock draw bulbs (which tend to cause the insulation to get soft by overheating the wires).

You may also want to look at my CyberPoet's Headlight Diagnostics, Troubleshooting and Repair Page, at MotorcycleAnchor.com - providers of superior security solutions. (ignore item #5, as your bike does not use a headlight relay).

Cheers
=-= The CyberPoet

[Red Kat]

Hey Cyperpoet thanks for the suggestions. I think though as you said "A" is eliminated as the signals work fine as do all other lights. "B" I inspected as I thought of that but it has pefect continuity in both positions. I did give the battery contacts and terminals a good cleaning but I guess it may be a problem somewhere in the harness but if it is shorting out why doesn't it blow the fuse??

I am still confused?? Anyone?

[The CyberPoet]

Hey Cyperpoet thanks for the suggestions. I think though as you said "A" is eliminated as the signals work fine as do all other lights. "B" I inspected as I thought of that but it has pefect continuity in both positions. I did give the battery contacts and terminals a good cleaning but I guess it may be a problem somewhere in the harness but if it is shorting out why doesn't it blow the fuse??

I am still confused?? Anyone?

You misunderstood what I said. A is the most likely culprit. Probably where the common ground leads back from the bulbs, although it could also be between the hi-/lo- switch and the bulbs themselves.

Here's the Wiring Diagram (98-02 Kat's; does not show headlight relay of the '05 model year, nor the passing switch of the '03-'05 model years).

Look at the harness connector by the top center of the page -- I suspect either B/W wire shared as the common ground by both headlight bulbs & the high-beam indicator light, or the matching pin on the harness pigtail connector (marked HARNESS 2 and HARNESS 1). Remember that because the ground is common to the front blinkers as well, shorted insulation there will also lead the headlight power back to ground.

Cheers
=-= The CyberPoet

[xbubbax]

also i wqould check the headlight relay/flasher thingy. that might have a condensation leak. or just faulty. also all the ground connections like cyber sugested

[furitive_revolution]

same thing happened on my car a couple weeks ago. luckily i was driving at midnight so i couldn't see anything! it turned out to be a worn wire and needed to be spliced then put back together. maybe the same problem?

[SweetLou]

From what I understand, it was a bit of a comon problem. I had the same problem as well a few years ago. I brought it to the dealer and had them fix it though as it was still under warranty. Turned out there was a loose connector or somthing like that. Anyways, they replaced the connector. Check your wiring up near the headlight assembly itself. Bike on and everything, and start jiggiling things to see if they go on or off. Mine started out to where I thought I noticed the headlights going off every now and then as I was going home at night. Then one day, they stopped working all together. The 3rd eye light is on a whole different wiring system, so that should stay lit.

Good Luck!

[trinc]

well if the left turn signal works the common ground is probably good. get a length of wire ( suitable size ) and connect one end to the battery (+) side & the other end to the (y) or (w) wire on the bulb connector . if it works - work backwards to the connector,switch & fuse box. at some point the lights won't work.

let us know where

tim

[Red Kat]

Hey Everyone,

Thanks for the tips and suggestions but currently the lights are working fine but if they happen to fail again soon I will try to pinpont the failure point using the wiring diagram from Cyberpoet (Thanks!) and the piece of wire to the battery (or my multitester continuity check) from the bulb and follow back to the fuse block / switch as suggested by Trinc. I should then be able to diagnose the failure spot assuming I'm home and it is still not working.

Also a thanks to Lou for his help and I may take off some fairing and do some shaking and twisting near the fron to see if there is a loose connection.

I'll keep you posted.

[gottagofaster]

Just a side note, My 03 Kat did the same thing with about 30 miles on it.Unfortunately i was riding it about 65 mph on a dark highway at night.I went to switch the highbeam to low and thats all she wrote, No more headlight.Ended up in a minor lowside.
The strange thing was it was the terminals in the switch.They got so hott the switch literally melted itself.I dont know if your problem is related just thought I might warn you what happend to me.My dealer coverd all repair costs.And interesting enough there was three other Kats there with the same problem.

[The CyberPoet]

Just a side note, My 03 Kat did the same thing with about 30 miles on it.Unfortunately i was riding it about 65 mph on a dark highway at night.I went to switch the highbeam to low and thats all she wrote, No more headlight.Ended up in a minor lowside.
The strange thing was it was the terminals in the switch.They got so hott the switch literally melted itself.I dont know if your problem is related just thought I might warn you what happend to me.My dealer coverd all repair costs.And interesting enough there was three other Kats there with the same problem.

I've heard a few other reports of this for the late '02 and early '03 model year (possibly your own statement at the time, plus NHTSA has three complaints on record for the '03 model year lighting - bandit & kat). I don't recall seeing a TSB or recall for it though, so I'm sure Suzuki is paying all the repair costs to keep it quiet and simply got a defective batch of switches from their vendor.

The only recall I am aware of for the Katana platform is a recall of 1998 model-year 600 & 750's for replacement of the rear passenger grab rail and mounting bolts.

Cheers
=-= The CyberPoet

[Red Kat]

Update! Problem Solved

Hey everyone just an update that the problem is finally fixed. It took a while because the damn light would never fail or stay failed until I could get home to my diagnosis equipment but last week it stayed out until I arrived at my parents just prior to sundown. Well we battled the mosquitos and with the help of some advice here and from Suzuki Canada's technical expert we identified the "Right handle bar switch coupler loop" connector as the problem. Cleaned and adjusted the connector and now we have solid contact and no more lights out! Posted below in italics is the email text from Suzuki:

We have no record of this symptom on another GSX750F, therefore a fresh start must be made to diagnose the malfunction on this motorcycle.

Since we know that all other lights, horn, ignition, etc. are not affected, the testing can be isolated to only the part of the circuit that affects the high bean and the low beam. Since there are only a few components and connections in this circuit, the diagnosis can be straight forward if the technician has a thorough understanding of layout of this circuit according to the attached wiring diagram. Since the problem could be a loose connection at a harness coupler, a damaged wire, the left handlebar switch, the High or Low beam fuse or fuse holder or the headlight bulbs, the body work should be removed for access and a voltmeter used to isolate the part of the circuit that has malfunctioned.

The malfunction will be one of the following parts which are included in the high and low beam circuit. It is not necessary to test wiring, connections or parts other than these.
- Right handlebar switch coupler loop (O to O/R to Y/W) (power to circuit when ignition switch is ON)
- Y/W wire in main harness from Right handlebar switch coupler to Left handlebar switch coupler
- Hi/Lo Dimmer switch which is part of left handlebar switch
- Y/Bl wire from Left handlebar switch to 15A high beam fuse
- Y wire from 15A high beam fuse to Right and Left high beam headlights
- W/Bl wire from Left handlebar switch to 15A low beam fuse
- W wire from 15A low beam fuse to Right and Left Low beam headlights
- Headlight bulbs
- B/W wire (ground) from Right and Left headlights to main wire harness

[SUPA-FLY-KAT]

well if the left turn signal works the common ground is probably good. get a length of wire ( suitable size ) and connect one end to the battery (+) side & the other end to the (y) or (w) wire on the bulb connector . if it works - work backwards to the connector,switch & fuse box. at some point the lights won't work.

let us know where

tim

A FRIEND OF MINE HAD THE SAME PROBLEM , AND IN ADDITION THE LEFT BLINKER WENT OUT TOO (IN ADDITION TO THE HEADLIGHT AND DASHLIGHT)? THE RIGHT BLINKER WAS GOOD. ANY SUGGESTIONS OR HELP? THANX ALOOOT

[The CyberPoet]

A FRIEND OF MINE HAD THE SAME PROBLEM , AND IN ADDITION THE LEFT BLINKER WENT OUT TOO (IN ADDITION TO THE HEADLIGHT AND DASHLIGHT)? THE RIGHT BLINKER WAS GOOD. ANY SUGGESTIONS OR HELP? THANX ALOOOT

Water in the left-hand switch assembly, and/or bad connectors to the dash assembly. What year/bike?

Cheers
=-= The CyberPoet

[SUPA-FLY-KAT]

(((HI THERE MARK ! HOPE ALL IS FINE. I HAVE BEEN BUSY WITH SUMMER CLASSES FOR A BIT BUT IM STILL WORKN ON OUR PROJECT..., I THINK I FOUND S MANUFAC. WHO CAN PUT THE WHOLE THING 2GETHER, WITHOUT WELDING/GLUE...ILL PM YOU MORE INFO AFTER THE JULY 4 HOLIDAY.)))

HE HAS A 98KAT 600. I THINK THE PROBLEM ARISES WHEN THE BIKE OVERHEATS AND STARTS TO SMOKE..(IN HI TRAFFIC)....MAY NEED TO TAPE THE WIRES...., BUT WHAT BOGGLES ME IS THAT Y THE RIGHT BLINKER WORKS FINE?