removing Li type headlight switch with VERY RUSTED screws?

[vegansydney]

Any tips for removing an Li type light/horn switch with very rusted screws? Would like to save the switch so heat is not really an option.

I've got an pre-registration inspection (local MOT equiv) on Wednesday and just realised horn is not wired up on my rusto project.

Alternatively, anyway to wire up the white horn wire without removing the switch? All other electrics are working sans the horn which I've not wired up. There doesn't appear to be a white wire from switch. Apologies electrics are NOT my strength

Specs:
1969 GP200 Oz market (Li switch), AC electronic 12v, MB simplified loom, the rest as Innocenti intended.

[carlos fandango]

I think the only way is with heat and penetrating oil, it doesn't need a great deal of heat so shouldnt damage the switch. Just take your time, gentley heat around the switch housing and spray with penetrating oil, let it cool then repeat five or six times. Heating the ally will make it expand more than the steel screws which should allow the oil to penetrate
The problem you will have is that the with the switch cover on, its difficult to get the penetrating oil in the right place
Alternatively drill the screw heads off, this will let you take the switch off ,but more importantly leaving the shank of the screws intact so you will be able to do the above with heat and oil, and still have something to hold to get the screws out.
If you havent got the time to this before wednesday, temporarily fit an extra switch for the horn and then do the above at your leisure. the white wire from the horn to the switch just needs to be earthed to activate the horn.
Hope this helps
Russ

[vegansydney]

Thanks! Followed your advice and got it off. Much appreciated.

Next question where does the horn wire go according to this pic? According to the wiring diagram it should be in opposite the purple (bottom RH cnr of picture below). Is this correct?

Reluctant to start pulling out existing wires as everything else is working.

[Hotspur]

Don't pull any wires out. If you undo the two screws at either side, you'll see the horn wire, and how it's earthed. You never know, it may just need a clean up.

Pete

[vegansydney]

OK, that makes sense. Sorry electrics are not my strength

Yet, according to the diagram, there should be a white wire from the actual horn to the handle-bar switch. As it stands everything is working sans the horn as I only have purple from the loom currently plugged in there. The other other horn terminal is currently empty. Do I need a white wire from the switch the horn terminal as per the diagram?

[Hotspur]

I think I understand what you mean. Yes you should have a wire from the horn to the switch. The way to test this out, is (I assume LI with no battery) connect a wire from the spare horn terminal to earth, and kick it over. If you hear the horn, then that is working OK. You then need to run a wire from the spare terminal to your switch, and all should be OK. Hope this is understandable.


Pete

[RICSPEED]

thing is the horn works only if theres a good earth ,there isnt a earth wire returning from the switch and is having to earth through the switch then housing and then the head set ,an extra earth wire from the switch body skrews to the head set is a good idea

[carlos fandango]

OK, that makes sense. Sorry electrics are not my strength

Yet, according to the diagram, there should be a white wire from the actual horn to the handle-bar switch. As it stands everything is working sans the horn as I only have purple from the loom currently plugged in there. The other other horn terminal is currently empty. Do I need a white wire from the switch the horn terminal as per the diagram?

This diagram is for the gp type switch ( horn and dip) not the li type (horn dip and main beam to side lights)

But i would take the switch apart and clean the contacts its also easier to see what wire go's where.

[firekdp]

On a standard LI3 switch the white would go to the exact place you have a purple, so where does this wire go on your set up? I take it the ignition switch still controls the lights on/off and the lower switch was for indicators?

[vegansydney]

On a standard LI3 switch the white would go to the exact place you have a purple, so where does this wire go on your set up? I take it the ignition switch still controls the lights on/off and the lower switch was for indicators?

Correct. The ignition switch still controls the lights and the lower switch is still wired for indicators (thou they have been removed from the scoot). I'll check the purple wire this evening and see what it runs to.

FYI: The current set-up is 12v AC, running a BGM stator, SIL flywheel via a MB simplified loom. Scoot is 1969 GP200 which is Oz market spec (LI3 switch to run factory fitted indicators). Both the ignition switch and headlight switch retain factory wiring, only the loom has been replaced. All electrics sans the horn are currently working.

MANY THANKS!!