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Discussion Starter #1
This was supposed to be easy...
So I finally ordered some red LED push buttons to swap out the climate control and headlight buttons.

Then I encountered the black cap of apathy. I have tugged on this thing, and short of channel locks, it isn't coming apart. I need to reuse it to plug into the new push buttons. If anyone has done this before, let me know. Or I'll just have to grab vice grips and chance the catastrophic results! ImageUploadedByAG Free1415490314.568804.jpg


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Well... I messed up and got impatient. Pulled a bit hard and the green base separated and broke...

Now it appears the base is glued into the black surround... Possibly soldered? I think I need to break more things. Plus, with three wires and four connections on the new button (with no indicators as to what goes where), I think I just stepped into "oops" territory. Nothing to do but keep going!


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The only indicator I have is that some of the posts are longer, and on one of the long posts there is a notch under the hole in the posts (negative maybe?) I shouldn't have started with the headlights, but I did... Could use some help here. ImageUploadedByAG Free1415494550.536269.jpg ImageUploadedByAG Free1415494565.991848.jpg


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Okay, cut off some of the glue (anyone know what type of glue this is?) and it appears that the notched longer pin/tab does not have anything connected on the green indicator. Clockwise from that there is the black wire with a green strip, then red, then blue. Any electrically inclined person know if this sounds right?


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Yikes. I remember trying to get those off and just saying screw it. Good luck
 

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Discussion Starter #8
So I wired the way it looked correct and it turns on the lights. The red LED does not light up though for some reason? I'm thinking solder it to another post. What do you guys think? Yeah?! Ok. I'll try it.


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The LED needs a positive post and a negative post in order to light. If it's reversed it won't light.


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You need to figure out which posts are positive and which are negative out of the 2 silver and 2 copper posts. This will give you a definite orientation in order to complete the circuit.


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Color alone would typically signify negative/ground. But with an automotive harness colors aren't necessarily conventional.


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Discussion Starter #14
Unfortunately they are all silver. It's very odd. I switched the black/green and blue wires to the opposing posts, and the lights still work. Still no LED though.


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I would think red is pos, black is neg and blue grounds the power to the lights when switched on.


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Discussion Starter #17
So was I. All the tabs are silver on the back of the switch. Oddly when I move the blue or black to opposing tabs the lights still work. I have tried switching the red wire to either remaining tab to no avail.


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The switch you're holding in the pic appears to have 2 longer silver tabs and two shorter copper or gold color tabs on the back of the switch. Is that the new switch?


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Is there a part number for the new switch? It should have a datasheet that says what all the pins are..

Found it - APEM switches. Page 5 - http://www.apem.com/files/apem/brochures/switch-pushbutton-IP-mom-ENG.pdf

Blue is ground, it switches to the Normally Open contact Black, and Red is the LED +.

Looking at the Bottom / pin side of the switch, if the machined flat (in the chrome housing) is facing AWAY from you (long pins will be on left and right), the TOP pin is Black, the RIGHT pin is Red, and the LEFT and BOTTOM pins are shorted together with the Blue wire. That's looking at the Lotus switch, I can see through the clear epoxy where the wires are soldered. The data sheet doesn't help much with the bare-pin version of the switch! Very odd. You can actually see the connections in the pictures below - very simple, 2 side ones get shorted by the metal bar on the push-button, the other 2 are the LED contacts. There's 3 wires because they're sharing LED- and one side of the switch.

Oh yeah - the OEM switches are the same as the ones you have, the factory (APEM) just solders the wires on, puts that black cap over them and fills them with epoxy instead of heat-shrinking the individual pins. Definitely won't come off, need to cut the wires if you're replacing the switch - it's not a connector. Then Lotus crimps on the green car-side connector (you can buy them from Mouser) and marks them up 300%. :)

I changed mine to red some time back - I took them apart carefully (you have to gently pry back the crimped metal bottom to release the green part)

Finished:



Pry bottom crimped section open with tiny screwdriver:


Pull apart:


Separated - you can see the simple metal bar that closes the 2 contacts when you push down:


LED inside:


Close-up of LED and switch contacts (left/right):


LED VERY carefully removed - tiny soldering iron tip and a microscope really do come in handy.....:


OEM LED on the left, replacement on the right. OEM has solder terminals spread into 'notched wings' that are soldered to the terminals inside...:


Replacement PLCC-2 LED, I manually flattened and spread the contacts, then clipped them into a sorta-similar shape as OEM so they'd reach the terminals:


Lit up - Note, there is a resistor 'somewhere' in the Lotus that drives this LED. So if you measure with no LED, you'll get 12v, which you'd think would blow the LED (2v). But the current limiting resistor IS there, it's just in a control module somewhere..
 
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