A few days ago I had the joy of a headlight switch failure....flipped up...no light. Fuses fine. I cleaned off the terminals of the switch but to no avail. I was just about to drop $50 on a replacement switch when I decided to tear the switch apart to see what its failure actually was.

Okay so I should have taken pictures...I know.

I carefully pried the bottom plate off the switch....there are two notch tabs on each side....I found that the side that is split into two small tabs was easiest to pry back releasing the switch guts....

Do this over a piece of paper...Not the carpet like I did....as there are 9 micro thin springs which support 3 funny shaped metal contact tabs that went EVERYWHERE. As well as the spring loaded switch bearing...that gives the switch that "click".

So it was pretty clear, upon opening, that the 27 year old switch was completely fouled. Most of the pads were completely black with a groove where the contact tabs engaged. The Headlight pad and contact tab were completely carbon fouled....explaining my lack of headlights.

I used some fine sandpaper, cleaned everything up, then swabbed a fine coat of conductive grease on the contacts....then fumbled around trying to reassemble....Ill spare you the failures and tell you what worked.

There are 3 grooves in the switch that the switch bearing will rest in during switch action...drop the bearing into the middle groove...

put a dab of conductive grease, because I already had it out, onto the spring and insert it into the contact carrier, to prevent the spring from just falling out when you invert the assembly.

Flip the carrier and place the 9 springs back in their respective holes.

Holding the switch in the middle position, align the contact carrier and hold it in place with your thumb, compressing the bearings spring slightly.

Using tweezers, or your fingers if youre more dexterous than I, place each of the 3 contacts on their springs....you might want to test fit them before reassembly so you know which goes where....they are very similar in appearance though different enough to prevent them from being swapped with each other.

gently release the pressure you are applying with your thumb from the carrier....this is when things go wrong...and you have to start reassembly over....so release the pressure SLOWLY. The carrier will rise up a bit and if you are not careful will tip slightly either causing the contacts to fall or the ball to free....Provided everything stays in its proper place.... carefully snap the switch back plate into place.

While this may seem simple to those of you who have already done it....and it may be common knowledge...I did not find any writeup in my search...I only found explanations that flip up without light was probably a bad switch... Sorry for the lack of pics...but I didnt even think of writing this until my repair was successful and I realized that a post like this would have saved me ALMOST spending $50. So I hope whomever's search results hit this thread will find it useful.

 

Interesting and complete DIY.

This made me smile:
"Do this over a piece of paper...Not the carpet like I did....as there are 9 micro thin springs which support 3 funny shaped metal contact tabs that went EVERYWHERE.
As well as the spring loaded switch bearing...that gives the switch that "click". "

I may never get it back together after I smash it with a hammer.

Thanks,
John

 

More info on the head light switch:

http://forums.pelicanparts.com/porsc...ht-switch.html

Just FYI
John

 

mine had none of the scary warning signs...
no smoke
no melted wires
no external damage
Just oxidized terminals and a bit of corrosion on the plug
When cleaning everything externally didnt help...
I removed the switch
disconnected the headlight motor
raised the headlights manually
and jumpered the switch plug
headlights lit up

so I was sure it was a bad switch

I was ready to drop $50....but I figured if I was going to spend the money....I might as well try to break something first.

The innards of the switch, not unlike the power window switches often do, just needed a good cleaning. I imagine that many of the bad switches that have been replaced could have been "refurbished"...well at least the ones that werent burnt and melted.

I am considering wiring in a relay in the near future.....just doesnt seem necessary to have full headlight current going through the switch...especially after seeing how small the actual contacts are internally.

 

Good work. You have a lot more patience than I do, I would have just replaced it.

 

Normally I would have as well....
it was already too late to get the new one shipped out if I placed the order...
So I decided to "investigate" before my order....in all it took me about 30 min to save $50 so it was certainly time well spent.
In fact..now that I think about it..I spent longer writing about it then doing it.