Brakelightswitch a cutaway view

[Old Rider]

I had some brakelightswitces failing  (not only the fj) so i cut one in half to see whats going on inside .Rusty !!! obvious the wd-40
service at the spring tip i use to do not working because there is a little O-ring inside .

[red]

Old Rider,

You should know, WD-40 is mostly just kerosene.  The money they want for a few ounces of that old "farmer's wisdom" is insane.  I don't know if kerosene will ignite inside the switch, but I would guess that it is possible.  There are lots of aerosol-can lubes that are not just fuel, not flammable.  

The Model-T Ford would run all day on straight kerosene, but you needed to run the last mile on gasoline, or else the Model-T could not be started easily, next time.  People would install two fuel tanks, with petcocks, to make the fuel change-over easy when they got close to home.  Once started on gasoline, you ran the Model-T on gasoline until the engine was fully warmed up, then you could switch over to kerosene fuel (which was much more available than gasoline).  I love history . . .

Just a thought, but I'd suggest testing any spray lube on an open flame (outside) before using it in an electrical switch.  Many lubricants (including kerosene) are insulators, though.  WD-40 evaporates to leave a gummy residue behind.

As an alternative, I could see using RTV sealant to waterproof every seam and opening of the new switch body.  If you use some thin lube on the moving shaft first, you can seal that opening with RTV as well, and once the sealant cures, the shaft will still move and seal, better than having only a simple O-ring there.
.

[Old Rider]

Old Rider,

You should know, WD-40 is mostly just kerosene.  The money they want for a few ounces of that old "farmer's wisdom" is insane.  I don't know if kerosene will ignite inside the switch, but I would guess that it is possible.  There are lots of aerosol-can lubes that are not just fuel, not flammable.  

The Model-T Ford would run all day on straight kerosene, but you needed to run the last mile on gasoline, or else the Model-T could not be started easily, next time.  People would install two fuel tanks, with petcocks, to make the fuel change-over easy when they got close to home.  Once started on gasoline, you ran the Model-T on gasoline until the engine was fully warmed up, then you could switch over to kerosene fuel (which was much more available than gasoline).  I love history . . .

Just a thought, but I'd suggest testing any spray lube on an open flame (outside) before using it in an electrical switch.  Many lubricants (including kerosene) are insulators, though.  WD-40 evaporates to leave a gummy residue behind.

As an alternative, I could see using RTV sealant to waterproof every seam and opening of the new switch body.  If you use some thin lube on the moving shaft first, you can seal that opening with RTV as well, and once the sealant cures, the shaft will still move and seal, better than having only a simple O-ring there.
.

Hi Red
cool story about the T-Ford !yes i know the wd-40 is flammable but i think that's just the propellant.I had the ignition off when spraying I have 2 other
spraycans with contact spray and contact cleaner but found the wd40 is best when keeping moisture and the rust away in contacts.I don't think the other contactspray
has rust a inhibitor in it .Only drawback with the wd40 is it collects dirt,but used sparingly and wipe the excess off its not to bad. It is also easy to clean
off later with the contactcleaner if needed.
I use it in my handlebar switches and in the ignition and coil wiring plugs also .
Many years ago on the fj1100 i often had trouble with starting it after washing the bike.Sometimes i had to do a running start to get it started .After i put
some wd40 into the coil and ignition wiring plugs and a drop inside the spark-plugcaps the problem starting it after a wash was gone .I do the same on the 1200.
The brake light switch is supposed to be water resistant i think because the wiring is melted/sealed in the rubberboot see picture.
There are some places i don't use WD-40 and that is on the carburetor linkage that will get messy and dirty. There i use silicone spray instead.
A place i never ever would use WD-40 iis the place this guy uses it that would have killed me   .https://www.youtube.com/watch?v=2lW4TvRTQKk

[red]

Old Rider,
Just a thought, but I'd suggest testing any spray lube on an open flame (outside) before using it in an electrical switch.  Many lubricants (including kerosene) are insulators, though.  WD-40 evaporates to leave a gummy residue behind.
As an alternative, I could see using RTV sealant to waterproof every seam and opening of the new switch body.  If you use some thin lube on the moving shaft first, you can seal that opening with RTV as well, and once the sealant cures, the shaft will still move and seal, better than having only a simple O-ring there.

Hi Red
Many years ago on the fj1100 i often had trouble with starting it after washing the bike.Sometimes i had to do a running start to get it started .After i put
some wd40 into the coil and ignition wiring plugs and a drop inside the spark-plugcaps the problem starting it after a wash was gone .

Old Rider,

Yeah, the reason why you had starting success after a wash is because you were using WD-40 for the ONLY purpose that it was ever intended to do.  WD stands for Water Displacement.  The guy came up with it to displace water on engines that were wet with water or coolant and would not start.  It only took him forty tries to find the right stuff, or so he claimed in an interview, long ago.  It is still a poor choice on things that you WANT to conduct power, such as switches, due to that leftover gummy residue which attracts dirt.  
I would still favor RTV to waterproof a new switch from the first, before the fact.

[ribbert]

Yeah, the reason why you had starting success after a wash is because you were using WD-40 for the ONLY purpose that it was ever intended to do.

[Charlie-brm]

I'm curious why dielectric grease has not come up as a suggestion. That's my go to. I separate a variety of connectors and dab in some of it once a season if I ever remember to do it

[giantkiller]

I'm curious why dielectric grease has not come up as a suggestion. That's my go to. I separate a variety of connectors and dab in some of it once a season if I ever remember to do it

Was thinking the same thing. I keep it in a big syringe. Very large needle. To get it into tight places.

[red]

I'm curious why dielectric grease has not come up as a suggestion. That's my go to. I separate a variety of connectors and dab in some of it once a season if I ever remember to do it

Charlie,

Dielectric means insulating.  Not what I would want in a switch. 
I know people use it to block corrosion, but you need to have very good contacts, if that grease is your choice.

[giantkiller]

Good to know didn't know it interfered with contact. Never used it on a switch though.

[indyblue]

I'm curious why dielectric grease has not come up as a suggestion. That's my go to. I separate a variety of connectors and dab in some of it once a season if I ever remember to do it

Charlie,

Dielectric means insulating.  Not what I would want in a switch.  
I know people use it to block corrosion, but you need to have very good contacts, if that grease is your choice.

It doesn't literally insulate a connection, it just doesn't conduct.  You would not want anything conductive around electrical breaker/switch/connector contacts, that would cause a short.  It will not insulate switch contact points but will lubricate, protect the connection and prevent arcing.  Perfect for this application where parts may be in a wet environment (IMO).

From somewhere on the innerwebz:

Dielectric grease is also known as tune-up grease. It is a silicone-based and non-conductive type of grease to protect electrical connectors from corrosion, moisture, and dirt.

[Old Rider]

I always used wd-40 but
Seems dielectric grease would have been a good option on the brakelight switch with a syringe to get it inside the brakelight switch . My turnsignal switch is a little sticky so
its time to open it up and use  dielectric grease in there it also seem to prevent heating/melting of contacts so it will be great to use in the red connector coming from the generator.
Found this video about the dielectric grease but i would not use it on the headlight bulb contact on the fj  it might be so hot that it will fog on the reflector.

dielectric grease  https://www.youtube.com/watch?v=zhl3bLzgq9A

he also  uses wd-40 but mayby a little too much 

wd 40 https://www.youtube.com/watch?v=JyuFEroKnno

[Motofun]

The U-tube guy is wrong.  Not in his application but in his understanding.  Dielectric grease does NOT conduct, rather it insulates.  You still must have metal to metal contact in the switch or connector in order for it to work.  The grease just acts more like a continuous seal to help keep out air and water.

[giantkiller]

Yeh don't use it on the headlight plug...I was in the smokey mountains. In the middle of nowhere. About 2am and my headlight went out. Sped up to get behind the one vehicle on the road ahead of me.  Freaked him out at first. Then he figured out what I was doing. Followed him until I  got to a gas station with a light. Took a  while but I found the plug came loose. Down on the  ground. Sticking my arm up in there got it plugged back in.