GS450 High Beam Switch Suddenly Became the Ignition Switch

[GS450oLd]

No, the title is not a typo.

I have a 1982 GS450.
I was out riding when someone puled out in front of me and I blared the horn.
After I let off the horn button, I could hear the starter was suddenly running continuously.
After a little confusion, I found that the high beam being on was inexplicably powering the starter motor. (I typically ride with the "high beam" on because the headlight is so dim)
When i toggled the high beam off, the starter stopped.
Now when I attempt to start the bike, the normal starter button doesn't do much of anything.
To start the bike, I have to toggle the high beam switch to the on position (doing this continuously cycles the starter), then once the bike fires up, turn the high beams off to stop the starter from cycling continuously.

Interestingly, you do not have to hold the clutch lever in when using the high beam switch to cycle the starter motor.
Even more interestingly, and with the stop/run switch in the "stop" position, if the key is in, turning the high beam switch to "on" still cycles the starter EVEN THOUGH THE STOP/RUN SWITCH IS SET TO "STOP".

I am at a loss here.

[hillsy]

Has this been happening the entire time you've had the bike or just "suddenly happened"?

If all the time, then someone has probably mucked up the wiring at the switchblock connectors - check the connectors against the wiring diagram.

If all of a sudden, you have probably developed a short / crossed wire in the harness somewhere - check the harness for pinches / cuts / abrasions / damage.

[GS450oLd]

It never did this until today. Suddenly it started doing this after I pressed the horn button.

[sam000lee]

Maybe your bike is haunted, otherwise something must have been knocked loose if it is a new behavior. Have you looked at the wiring diagram from http://members.dslextreme.com/users/bikecliff/

[sam000lee]

I would check around this connection - it's where the horn/headlight grounds meet. Neither of my 450's had the Starter Disconnect Switch so I'm not sure how the wiring is routed but it could be that somehow the high beam wire (White/Black) got shorted into the Starter Disconnect (Yellow/Green) between it and the starter relay...




EDIT: Looking again - also check the terminals of the Yellow/Green wires of the Starter Disconnect Switch. Maybe one of them (the one going to the starter relay) just came undone and is touching something it shouldn't.

[Steve]

I'm pretty much with sam000lee's last thought there.

First of all, does your bike have the clutch interlock switch? It has been suggested that not all years of the 450 had them.
If you do have the interlock, the yellow/green wire that triggers the starter solenoid comes from the "kill" switch and starter button, then across the handlebars to the clutch interlock and finally to the solenoid. If that wire happens to touch the high beam wire inside the switch housing, it will operate whenever the ignition key is ON and the beam selector is in the HIGH position, regardless of the position of the "kill" switch.

I would start a search in the left switch housing, then follow the wires down the handlebar, all the way until they go into the harness and go their separate ways.

.

[GS450oLd]

I'm pretty sure the bike has a clutch interlock switch, as you have to hold the clutch lever in to start the bike (during normal operation)
This is what the inside of my left switch housing looks like. I'm not seeing a yellow/green wire in there.

switch.jpg

I'm pretty much with sam000lee's last thought there.

First of all, does your bike have the clutch interlock switch? It has been suggested that not all years of the 450 had them.
If you do have the interlock, the yellow/green wire that triggers the starter solenoid comes from the "kill" switch and starter button, then across the handlebars to the clutch interlock and finally to the solenoid. If that wire happens to touch the high beam wire inside the switch housing, it will operate whenever the ignition key is ON and the beam selector is in the HIGH position, regardless of the position of the "kill" switch.

I would start a search in the left switch housing, then follow the wires down the handlebar, all the way until they go into the harness and go their separate ways.

.

[Steve]

I'm not seeing a yellow/green wire in there.

You are correct, that wire goes to the clutch perch on the handlebar, it does not go into the switch housing.

In that case, follow the wire bundle from the switch housing, it probably goes into the headlight bucket. Follow the clutch wire bundle, it goes to the same place. See if there is anything bridging across where the two bundles go near each other in the bucket.

.

[GS450oLd]

Ah ok, I misunderstood.

I found the problem! I followed the wires from the clutch interlock switch and the headlight switch into the headlight bucket, then out of the headlight bucket (it's kind of a quagmire in there, but nothing looked like it was worn through and/or touching anything it shouldn't have been). I followed that main wire loom down to its lowest point under the part of the frame where the triple tree attaches to the frame and there I found the issue. The wire loom had been worn through or cut through somehow and two wires had their shielding worn away and were touching each other. The starter relay wire and then high beam wire. Once I separated the wires, rewrapped them in electrical tape, then rewrapped the wire loom, everything is back to normal!


wireloom2.jpg


Thanks for all your help everyone.

You are correct, that wire goes to the clutch perch on the handlebar, it does not go into the switch housing.

In that case, follow the wire bundle from the switch housing, it probably goes into the headlight bucket. Follow the clutch wire bundle, it goes to the same place. See if there is anything bridging across where the two bundles go near each other in the bucket.

.

[GS450oLd]

Since it wouldn't let me put both pictures in one post, here's the wireloom the way I found it.

wireloom3.jpg

[hillsy]

Could the loom have rubbed on the front tyre under braking?

And why are you not running a front fender? You know they act as a fork brace, right?

[hillsy]

Since it wouldn't let me put both pictures in one post, here's the wireloom the way I found it.

[ATTACH=CONFIG]50824[/ATTACH]

Yep - definitely hit the tyre.

[Steve]

That is one of several reasons why the fender was put on the bike at the factory.

Glad that the problem is fixed, now fix the reason, too.

.

[GS450oLd]

It's all coming together now. When that person cut in front of me, I hit hard on the brakes, causing the front end to dive, which allowed the wireloom to rub on the tire and cause my issue here.

Makes total sense now.

Needless to say, the fender is back on, haha. Thanks for your help everyone.