GT500 Turn Signal Switch has lost its notchy-ness

[Mike MPD]

I feel a little silly asking this one. Ive taken apart many classic Japanese switch assemblies and they are all pretty simple and similar.

On my GT500 the turn signal switch has lost is ability to click into place for the three positions. I have taken it apart and cleaned everything and that will fix it for a bit, but after a few switches back and forth it will go full loose again. I think its the ball bearing sticking, or weak spring, or combination of the two.

Does anyone have a source for replacing just the internal switch mechanism? Any other remedy I should try? I'm hoping to not replace the entire LH switch assembly just for one sticky little switch.

Thanks,
Mike

[Alan H]

It's always nice to do a quick introduction before asking things. Just a hello with your name, general whereabouts and a bit of biking history.
Meanwhile, welcome in.

[Mike MPD]

Hi Alan, I suppose thats fair! I have had an account on here for a while and honestly didnt even realize this was my first post.

Im Mike from the USA. Ive got an RD400 thats nearing completion with Spec II stage 2 setup. Bike is running but has some custom work to finish up (seat pan, paint etc.)

Gt500 was purchased for a measly $450 USD. A few odds and ends to finish up but Ive gone through just about all the maintenance short of opening the engine (for now). Wheels bearings, rebuilt forks, fresh brake system, etc. Buttoning up the fuel system is the only thing left before trying to make it a runner but Im probably going to go ahead and do top end gaskets and such as well. Crank seals on the way also.

Some other bikes in my signature plus enough vintage mopeds that Id have to count.

[Alan H]

Thanks Mike, welcome in.
It's always nice when a new 'member' tells us what's what so that a technical question can get an answer that can be understood.
I've restored a few GT550S and each one has has a 'dieseled' crankshaft, whereby each case is filled with diesel and the engine is turned over - and over - and over and....you get the picture, then the diesel drained out and do it all again over a couple of weeks depending on how much spare time you have. This softens any rust on the crank where the seals run and also softens the seals so they don't tear as they would if they are started dry after being stood for 30 odd years.

[Mike MPD]

So I have discovered that the turn signal switch is shorting and grounding out through the spring, causing it to heat up and collapse. Which then makes the switch all loose.

In case someone comes across this in the future, McMaster-Carr # 9657K602 is an excellent replacement for the spring in the turn signal switch mechanism.
https://www.mcmaster.com/9657K602/

I am still trying to discover the root of the issue at hand though, as it was working perfectly fine not too long ago.

[Mike MPD]

This bike has been on the back burner for a bit but I wanted to provide another update.

I believe there may have been a piece isolating the copper contact in the switch from the spring and ball-bearing for the detent. Which makes sense I think.

So I am assuming that something must have fallen out when I disassembled the switch and I failed to notice. I am not sure if this will be a long term solution but I cut a small square of rubber to fit behind the copper contact and this fixed my issue!

If anyone has I photo of the correct piece to be used here, or something else they have used as a replacement I would be interested to know.

[gammakeith]

You can use a ceramic ball bearing as that is an insulator. I had to do that with a turn switch I cobbled together for my T20.

Keith