Article [13] ST1300 - How to: fix your intermittent microswitches at home!

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Jan 12, 2018
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Birmingham, AL
So, after beginning to have the seemingly common issue of the screen on my bike going up, but not down, I tore the front upper fairing off and decided i was determined to fix this.

I checked my voltages / grounds at the plugs for the up and down relays. Verified that I wasnt getting voltage to energize the relay coil on the down side, even with the switch depressed.

I took apart the left grip pod, and ohm'd through the switch at the bar. It checked good. That left my down limit switch as the only culprit.

These switches are tiny. I was hesitant to break one open, as it would likely mean a new $400 assembly if I was wrong, or physically broke it.

But, my determination to be a cheapskate won out...

I (gently) pried the "top" portion (with the mechanical arm) off of the switch. (Be very careful, as the little "tabs" on the corners that hold it on are easily broken.)

After getting the switch apart, I lightly sanded both sides of the "clicky" portion of the contact (that looks like it would be the problem area) and reassembled it, thinking I fixed it. No dice. Still no movement and no voltage at the relay coil.

I took the switch all the way apart this time, to figure it out.

In the photos below, you'll see the inner workings of the microswitch and how it works. The "spring" for lack of a better term acts as a part of the circuit.

When the windshield assembly moves down (or up) it depresses the silver lever outside the switch. This pushes in on a small black plastic tab that passes through the green housing, and pushes down on the middle of the spring/conductor, causing it to make contact and "click".

The small curved section of the spring/contact makes contact with the center "post" inside the switch, being held there in tension by the other end going around the "post" on the end of the switch. (This "post" is not part of the circuit)

The center "post" that the curved part of the spring goes against, is where the corrosion was in my case.

I cleaned it well with contact cleaner and a wire brush (gently).

I gently reassembled the switch, and reinstalled the switches on the drive assembly.

Viola! She works like a champ now.

Here are some illustrations, so you can see what you are getting into before attempting this...

First, the diagram I used...

Windshield Wiring Diagram

















Hope this helps save some folks some money. (It certainly saved me $400).

-Tim
 

CruSTy

My Perception is my reality.
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Here are some illustrations, so you can see what you are getting into before attempting this...

Great DIY fix. This looks like a commercially available limit switch. I searched for the PN in the picture you posted but came up empty. Is there a manufacturers stamp or other PN on the other side? Might be able to find a replacement from Digikey. Next time I have the cowl off I will definitely be spraying some contact cleaner and lube in there.

Found this one at Digikey 255-3824-ND
Not an exact match but might be able to swap parts to make a new switch. It has the same specs 125V and 2A. $3.64 plus tax and shipping.
ABJ151460.jpg
 
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Nashcat

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@Smitty908

That’s also one of the best pictures of the location of the troublesome yellow connector.

John
 
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Just to add a tip from my electronics days; while sandpaper can work, the best to for cleaning electrical contacts is a "contact burnisher". They're made to polish contacts without abrading them in the process.
 
OP
OP
Smitty908
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Great DIY fix. This looks like a commercially available limit switch. I searched for the PN in the picture you posted but came up empty. Is there a manufacturers stamp or other PN on the other side? Might be able to find a replacement from Digikey. Next time I have the cowl off I will definitely be spraying some contact cleaner and lube in there.

Found this one at Digikey 255-3824-ND
Not an exact match but might be able to swap parts to make a new switch. It has the same specs 125V and 2A. $3.64 plus tax and shipping.
ABJ151460.jpg
Crusty, the contact positions are correct on that, (NC,NC, and O) but the mount holes are wrong. The top half is definitely the same though, and I would wager that the spring / contact inside is the same. I might just order a couple of these to have as spares in the future.

Good find!
 
OP
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Smitty908
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Just to add a tip from my electronics days; while sandpaper can work, the best to for cleaning electrical contacts is a "contact burnisher". They're made to polish contacts without abrading them in the process.
Al-Hala,

Good point. I just used what I had on hand, but i doubt 1K grit took too much off :)
 

W0QNX

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If you don’t mind soldering lead wires and maybe modifying the switch mount, Amazon has 5 amp switches, $5.99 for a 5 pack.

Limit switch
Thank you for the part link John. I replaced mine today. All went pretty smooth considering where it's located.

I was able to remove the mount plate by only removing the upper fairing piece and the "dashboard" of the bike. Then I used a 1/4" ratchet with a 10mm socket on the bolts that the green arrow in the first post of the thread points to. This takes some skill as it's one fingertip only to remove the bolts past the loosening point.

I had to drill a .094" hole in the metal mount plate (after removal from bike) and the plastic backer plate (at the white X). The hole is inline with the other 2 holes and ends up right at the edge of the mount plate.

I soldered leads on the new switch and spliced it onto the old switch wires. Then install it all back on the bike.

Part:
Podoy KW4 3Z 3 Micro Limit Switch AC 125V 5A Hinge Lever


limits.jpg
 
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Joined
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martinez,ca
I had the same problem with the shield not operating some times. I took the front fairing off and sprayed the limit switches with a good contact cleaner, let them soak ,cleaned off excess and haven't had a problem in 6 years
 
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