Headlight and display no worky...Everything else fine.

[Gus]

I posted a couple of days ago. Just got an '81 GS750E.

So here we go. Tonight I went out. Rode the bike 3 blocks with the headlight on. Turned the bike off (Headlight switch on). Came back out 15 minutes later.

NO HEADLIGHT!!! No display lights either. Turn signals and brake lights work fine.

I checked the fuses. They're fine

The battery's new.

Clues?

Trust me...I'm getting the manuals.

[txironhead]

Any good at hotwiring? Your ignition switch could be shot.

[Gus]

Bike starts no problem. All other electronics work, including the shift indicator. Since that's part of the display, I have to assume that it's only the circuit containing the headlight and display lights that's the problem.

I checked the headlight fuse and it looks good.

[txironhead]

Try wiggling the key while the bike's running. Unless you had a weird surge that blew out most of your bulbs, including the headlight, the only thing that I know of that controls power to the instrument panel is the fusebox and ignition switch. See if you can locate the ground wire for the display and make sure it's getting good contact. I believe it's located in the headlight bucket.

Even though a fuse looks good it can be bad. Also, if the fuse box terminals are corroded things won't work right. You may have to pry the cover off of the back of the fuse box to see if there's any corrosion in there.

If all else fails, it's time to start cleaning connections one at a time.....

[blo]

When this happened to me, it was the earth/negative wire from the headlight ass. that was broken inside the wiring harness. Try identifying the negative cable and pull slightly on it's ends to see if it is broken.

-blo

[mwa423]

Check the hi/low switch and/or on/off swith (or both, depending on your bike.) If either of those connections aren't tight then your headlight won't work.

[Doctor Shifty]

You can buy a continuity tester that is a brass barrel with a light in it, a wire coming out the rear end with an aligator clip, and a very sharp point at the front end. The point is very handy for poking into wires to see if there is power - and therefore where the power fails.

The Suzuki wiring has some surprises, especially inside the headlight bucket. There are connections in there that have caught me by surprise.

I still can't figure why the starter switch earth return travels from the starter button, under the tank almost to the fuse box, then returns to the headlight bucket to a connector, then back towards the fuse box. When that connector worked its way loose I could push start the bike but the starter button was useless. Turning the handlbars sometimes moved the wires enough for the connector to connect, but not always. Having a "prodable" tester allowed me to chase that wire back and forth until I found the loose connector.

[Steve]

I agree with the Doc here, your best friend right now will be a good test light. Connect the alligator clip to the negative side of the battery and follow the circuit to the headlight. As mentioned above, remember that a good looking fuse is not necessarily a good conducting fuse. I have personally had more than one come unsoldered inside the tip.

The headlight circuit starts at the ignition switch. Using the book for my 850 (therefore, the colors might be different), there is a connector just below the switch that contains (among others) a red wire and a green wire. The red should be hot all the time, the green will be hot when the key is on. The green wire feeds the front marker lights (in the turn signals) and the meter lights, then goes to a 9-pin connector that is probably on the right side of the frame under the gas tank. There, it feeds a yellow wire that goes to the dimmer switch.

Happy hunting.


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