Electrical gremlin, a little help

[tommyz24]

Rode home one day, saw a little smoke in the headlight , shut off the bike. Next day battery is really drained.Bike wont start without a boost. The all of a sudden I take out the key, and the ignition is still on, headlights, lights gauges are all working without the key and I hear a noise coming from the battery area (buzzing) battery is weak and negative side is warm to the touch.

I'm going to check if something melted and is creating a ground, any other ideas?

[Toadstool Food]

Safety first Tom. If you have a short that is bypassing the ignition switch you have a real problem indeed. If you have not already, disconnect the battery starting with the negative terminal. A battery fire could toast your bike and even your house. Make sure you have good fire extinguisher handy (rated A , B & C ) just in case the unthinkable happens. Start behind the light and see what you can see. I dont know what your skill level is as far as electrical work goes, but you best option is to replace the entire harness if you find any wires seriously damaged.

[Mekanix]

Go here http://members.dslextreme.com/users/bikecliff/ Get a manual. there are two that cover the gs400-450 engines.

Almost everything is the same on the bikes if its a 400 or 450 except for the head which is 4 valves per cylinder on yours.

If its an E-model 450 chances are the E model 400 uses 99% of the same parts.

Here is a site to look up part numbers if you need to get something and need the exact number or if you want to cross check with other model's to see what's common.

http://www.cmsnl.com/suzuki-gsx400-1981-ex_model13617/partslist/

For your problem its most likely the plug for the ignition switch that has melted together or is shorting to ground inside the bucket.

Disconnect the battery and take the light out.

Look for melted wires.

Compare the wire colors to the ones in the wiring diagram in the manual's and see what they are for. The charging systems are weak in these bikes and will fail if original. Its a proven fact :P