The neutral switch on the GL1000 and the GL1100 up to '82 is notorious for the internal contacts becoming contaminated with carbon from the engine oil, resulting in the light still glowing with the bike in gear, brightening when it is in neutral.

Very common problem . The neutral switch is located in the bottom right of the crankcase and almost hidden behind the bottom frame tube. Not the easiest place to get at !!

You can get at it more easily by loosening off the bottom engine bolts (the engine won't fall out as the top bolts will hold it) and gently wedging between the engine and the frame.

Drain the oil first before removal!!!!!! This would be a good time to do an oil and filter change too.

Various ways have been mooted to clear the carbon off the contacts by overloading them with a heavy current to burn it off, but that seems to be a stop-gap remedy at best, with the condition returning sooner rather than later.

So I have always been under the impression that the best remedy was simply to replace it.

But wait!

Quite by accident I found something that I have not seen mentioned here or anywhere else when I had occasion to remove the engine.

I had been silly enough to Loctite the screw holding the wire to the switch, which meant that I couldn't undo it while the engine was in the frame. I had no alternative but to cut the wire.

Once the engine was out and I could get a decent purchase on it, DISASTER!, the whole base of the switch came loose in the body.

I couldn't leave it loose as I was sure there would be an oil leak, so what to do?

Since this is a brand new switch I didn't want to risk wrecking it so I took it out of the engine and examined it before doing anything else.

Looking at it, the base has the appearance of being moulded into the main body. But, there are four small blind holes in it.

Thinking about it I realised that it would be very difficult if not impossible to mould the base on when there is a spring loaded plunger inside.

Therefore the reasoning was that these holes were for a tool to tighten the base into the body.

Sure enough, the base can be unscrewed and then the components just fall out.

No problem now to clean the contacts of carbon!

The thread will have to be scrupulously clean and a little Loctite used to hold the base back in when re-assembling it all.

I think that if you could find or make a small pin spanner the switch could even be serviced in-situ (maybe, if you haven't Loctited the screw in the first place!)

This all sounds easy and so it should be. But I'd like to show you what you could come up against (picture 3)

It is said that you can prise the frame apart to get enough room to get the switch out.

That is up to you, but is not something I would ever contemplate doing!

Anyway, on one particular bike, I tried everything I could think of to get the switch out but eventually the engine had to come out. The corrosion holding the switch into the crankcase was so bad the I had to weld a bolt onto the switch body and then really bully the thing out!

So when replacing the switch in the cases, make sure that the gears are in neutral and it is greased with some copper based grease but do not grease the O ring or it will swell and give you trouble the next time. Or use a rubber grease as in the picture.

Make sure the switch goes in with the small oil drain hole to the bottom.

While you are in that area with the oil drained, remove the plate with the four bolts next to the switch, pull out the crankcase filter and give it a clean. You can also scoop out any residue from the bottom of the crankcase at the same time.