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Dang Brake light switch!

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RickB

RickB

Yoda
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Today I found my brake lights were on all the time, I don't think it's been this way for long.
Where can I get a dependable brake light switch?
I bought this one new from an ebay seller about 5 months ago, that didn't last very long.
 
Some of the new Lucas parts are junk right out of the box.
Repair your original switch. I have been repairing them for years. It is just a simple crimped case which can be pried open with a small thin screwdriver. The pin can now be taken out, cleaned along with the contact inside and it will be as good as new and last another 25 years.
Using the same screw driver and either a vise or helper to hold the case, just dimple the aluminum back to hold it together.
This same trick works with a Lucas flasher unit, stick the guts of a $3 Tung-sol flasher in your Lucas case.
Heck I have disassembled late model Jaguar power window switches, cleaned them and reused them.
 
And I do starter switches, the manual ones. They then again last for years and years.
 
The lights are ON all the time? Usually a bad brake light switch means they aren't turning on when they are supposed to. Are you sure it's not just out of adjustment? It's a normally closed switch (always on), so it needs to be screwed in just to the point that it's touching the pedal arm hard enough so it turns off, but not so far that the brake pedal isn't coming up all the way.
 
First thing I tried was the adjustment. Then I pulled the switch out & found the end with the little plunger stuck.
The plunger is broken.
It's stuck inside, can't be fixed.
I spent 20 years working with low voltage DC circuits, repairing switches like these. It's busted, gotta get a new one. I've no idea how this happened, doesn't matter - just got to replace it. Bottom line.
 
I burned through two replacement switches in less than a year. I finally got one that held together for about 3 yrs now. You might look at retrofitting a higher quality switch.
 
Thanks Trevor, where did you get yours?
I'm tempted to go get the switch off my MGC & see if it fits.
I've avoided plundering the MGC for anything because I really don't want to start down that road.
 
Ah, just thought I'd mention it, I was surprised that this was one of the failure modes of a Lucas brake light switch. I just had to replace mine, so I'll find out if my Moss replacement lasts.
 
The one I have now I bought as a used unit at a swap meet. The prior ones came from Moss.
 
That's not a very ringing endorsement for Moss.
Maybe I'll ask around my local MG club.
 
From what I can see of the picture, and as I am a Triumph aficiando, a suggestion. Junkyard shop for Honda/Nissan/Toyota from the 70's to the 90's as they used a brake switch(some also a clutch switch) that threaded into a holder. It appears similar in design to what I can see from the parts fiche picture. Might be able to get one of those to replace the Lucas one.

Also, Napa and Carquest have a parts illustration book on switches, get friendly with a counterman and browse through his switch book, might be able to find a replacement there that will cause far fewer headaches.
 
Thanks, that's a good idea - my NAPA guys are great.

I contacted the person I bought the last switch from, of course he says this is the first he has heard of any problem with the switch.

He offered to replace it after I mail him the broken one.
I'll do that, then at least I'll have an emergency replacement - but I want to find a better solution. Maybe a used MGB switch will work.
 
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