Author Topic: Brake Light Switch Spring Anchor Point (Read 2368 times)

Karl Childers · **on:** July 11, 2021, 05:33:43 am

Just when I thought I had everything sorted out with the brake light I am now dealing with the switch not working because the anchor point for the spring moves. It is the odd shaped galvanized piece with a number of holes that the brake rod passes through. With the spring disconnected it rotates around the rod, it would need to be stationary for things to work. I have not disconnected the rod yet because the cotter pin will be a PITA to reinstall so I figured I'd ask first, has any one dealt with this and what's the fix? I can see a few cobby solutions but I'd like to keep it factory if I can.

ddavidv · **Reply #1 on:** July 12, 2021, 03:13:45 am

Mine does the same thing. I got creative with all the other adjustments to make it work.

AzCal Retred · **Reply #2 on:** July 12, 2021, 04:37:23 am

That piece is a "cam" to allow rear brake switch on/off point adjustment by varying spring tension.

Mr_84 · **Reply #3 on:** July 12, 2021, 06:12:10 am

Quote from: ddavidv on July 12, 2021, 03:13:45 am

Mine does the same thing. I got creative with all the other adjustments to make it work.

same here works a treat now

Karl Childers · **Reply #4 on:** July 12, 2021, 01:58:37 pm

The one way I got it to work in any of the adjustment holes in the cam was to have it flopped as far to rear as possible. What I didn't like about that was the spring dragging in the bottom of the hole of the tool box. If I hold the cam at 12 o clock there is no drag in the box hole and the holes in the cam then allow for brake rod adjustments. The temptation to tack weld the cam in the upright position is overwhelming but I'll resist it for now and mess with some shorter springs with the cam in its flopped over position. Thank you all for your input.

AzCal Retred · **Reply #5 on:** July 12, 2021, 04:44:03 pm

Take your needle nose pliers and bend a hook in the spring until the length suits your needs. Nippers will remove and excess & make it pretty.

Mr_84 · **Reply #6 on:** July 12, 2021, 07:13:17 pm

Quote from: AzCal Retred on July 12, 2021, 04:44:03 pm

Take your needle nose pliers and bend a hook in the spring until the length suits your needs. Nippers will remove and excess & make it pretty.

👍right on there

Seipgam · **Reply #7 on:** July 13, 2021, 07:25:14 am

Karl,
Unless you have something different to this they are a simple and effective adjustment cam.
Mine was cocked up when I got the bike but as others have said a bit of a bend on the spring or an extra wire clip like I have easily sorts it out.

Geoff.

Paul W · **Reply #8 on:** July 13, 2021, 09:49:49 am

The spring on my brake light switch was made of non-springy steel, so it stretched. As already stated, the idea of the “cam” is to allow adjustment when this happens, rehook it in a different hole to ensure the brake light comes on at the correct time in relation to the pedal movement. I’ve previously re-formed the spring by pushing a round nail inside then pushing the coils back together with a flat bladed screwdriver. I eventually bought a new switch and spring.

Karl Childers · **Reply #9 on:** July 13, 2021, 12:33:31 pm

Seipgam, Paul and others, Thanks, I have seen the light and shortened the straight spring extension as per above photo and have the switch working great now. The other day in the workshop it was getting late and I was getting a bit punchy in my thinking, that's when I go down the ""what if the design were this" or "this would be better" rabbit hole and get lost in that fixation. Cool heads have prevailed and guided me back to reality, I'll save my redesigns for other more custom projects and stay true to the originality of this one.

AzCal Retred · **Reply #10 on:** July 13, 2021, 02:09:57 pm

Science Marches On! Here's another way to skin the cat:
https://www.automationdirect.com/adc/overview/catalog/sensors_-z-_encoders/magnetic_proximity_sensors

These have internal reed switch contacts and don't require a spring, just a piece of ferrous metal near the business end. Many have "C" form contacts, NO-Com-NC that toggle at proximity. No linkage, no nothing, just find a piece of iron that moves and sense it when it gets to the proper place. They are sealed units, so "lifetime" operation or 1,000,000+ operations...

Paul W · **Reply #11 on:** July 13, 2021, 02:57:38 pm

AzCal, I’ve used similar switches, but in other applications on my Liege trials car. I used one to sense a small magnet on the prop shaft, to provide a speed signal for the speedometer and a different type to sense brake disc bolt heads on the back of a front wheel, to provide a signal for a rally trip meter. Do you know if they can reliably take the load of a 21W brake light without a relay?

I found some online for a lot less than the prices on that website, mine were the equivalent of about $5!

AzCal Retred · **Reply #12 on:** July 13, 2021, 07:47:50 pm

You just figure out your specs & find the appropriate switch. They are great for on/off applications, I like the linkage elimination & hermetically sealed aspects. Just another option.

axman88 · **Reply #13 on:** July 14, 2021, 07:59:36 pm

Quote from: AzCal Retred on July 13, 2021, 02:09:57 pm

Science Marches On! Here's another way to skin the cat:
https://www.automationdirect.com/adc/overview/catalog/sensors_-z-_encoders/magnetic_proximity_sensors

These have internal reed switch contacts and don't require a spring, just a piece of ferrous metal near the business end. Many have "C" form contacts, NO-Com-NC that toggle at proximity. No linkage, no nothing, just find a piece of iron that moves and sense it when it gets to the proper place. They are sealed units, so "lifetime" operation or 1,000,000+ operations...

From the PDF guide on that site, it looks like the manufacturer is saying that the particular products you linked to, use electronic switching, so no "contacts", instead internal electronics culminating in a triac or thyristor.

The problem with electronic relays, in my view, is that sometimes, when they act up, they act very strange. To the mechanic who is thinking in terms of "open" or "closed", finding something that acts like a diode or a resistor when probed, can be pretty confusing. The old tech. was certainly a lot easier to understand. Remember when thermostats had a glass bulb with wires sticking out and a glob of mercury inside? Now that was something that anybody could understand. Not a lot of laymen can make much sense out of
"Magnetic sensors use GMR (Giant Magneto Resistive Effect) technology. The measuring cell consists of resistors with
several extremely fine, ferromagnetic and non-magnetic layers. Two of these GMR resistors are used to form a conventional
Wheatstone bridge circuit which produces a large signal proportional to the magnetic field when a magnetic field is present. A
threshold value is defined and an output signal is switched via a comparator"

AzCal Retred · **Reply #14 on:** July 14, 2021, 10:16:05 pm

Maybe I should have kept to a more generic "Magnetically Actuated Switch" and we needn't have gone down the electronic rabbit hole. These would require a magnet to activate.

In any event, these "prox" switches exist, are readily available, and just need to be selected to meet whatever spec's you require.
Sealed units are "black boxes". When they don't work exactly as specified, you toss them and go again.

https://www.amazon.com/Philmore-N-C-Magnetic-Reed-Switch/dp/B01IU7NWMM?th=1
N.O./N.C. Magnetic Reed Switch, SPDT
Current Rating: 0.5A@ 20V DC, 10 Watts (Max.)

https://www.mcmaster.com/magnetic-switches/
A savage amount of current & voltage possibilities.

https://www.mcmaster.com/proximity-switches/dc-metallic-object-proximity-switches-9/
DC Metallic-Object Proximity Switches
Also known as inductive proximity switches, these detect metallic objects even if they’re obscured by water, oil, dirt, or a surface finish. Sensing distance is based on the target material. The distance listed is for mild steel. They’re often used with programmable logic controllers (PLCs) and produce PNP or NPN signal output.

Some of these inductive proximity switches are in the $20 range and are good for 200mA of DC, 2.4 watts, so would work with via a suitable relay for a brake lamp.
The "Magnetically Actuated Switch" has a few examples good for 3A, so up to 36 watts @ 12V, so could easily directly activate an incandescent 1157 brake/tail light (2A/0.6A) or even better an LED brake lamp, but you'd need to give it a magnet to look at.
It's all just tinker toy stuff. Use it, or not, or keep what you got.

https://stevenengineering.com/tech_support/PDFs/38MAN_SENSOR.pdf
Red Lion has a "Magnetic Prox Switch" that has it's own internal magnet, so you don't need to add one.

https://www.superbrightleds.com/moreinfo/miniature-and-subminiature-bulbs/1157-led-bulb-dual-function-27-smd-led-tower-bay15d-bulb/2625/

mrunderhill1975a · **Reply #15 on:** July 19, 2021, 05:17:13 am

AzCal, you are a treasure of knowledge, this gives me great ideas for other projects, thanks for being here!

AzCal Retred · **Reply #16 on:** July 19, 2021, 05:41:53 am

Glad to share what I know. There is a universe of voodoo non-contact switches, measuring devices, etc. hidden in Newark, Grainger, Graybar, etc. Red Lion has some user-friendly stuff, as do many others. The manufacturers pamphlets are the best resource, and most companies have a help-line. There are many cigarette-package sized PLC's ("programmable relays") that are easily programmed, some have shareware you can download for free. 12, 24 & 48 VDC, 120 VAC are common power supplies and contact ratings. They're a hoot to play with, there are counters, totalizers, timers, all kinds of stuff built in. Prices are $100 - $400 range, and of course much more. They'd make a great basis for a PLC class. And for real fun, look at the 3-phase motor drives. ABB makes some nice ones, affordable in the 1 to 3.5 HP range. They have an incredible number of built in features. We are living in the freakin' future for sure...

https://www.driveswarehouse.com/?gclid=CjwKCAjwos-HBhB3EiwAe4xM9y8GXLp8qU8Pn-n0YyO_38uyQmNbgyQeL1-2PYK7ZwPzt9HAX8XiKBoCenAQAvD_BwE

Paul W · **Reply #17 on:** July 19, 2021, 08:53:59 am

Sometimes it's easy to get carried away and what should be a simple replacement of a standard part becomes a far more complicated and in in the end, more expensive, "project".

I bought my replacement "OE" brake light switch for less than $10....and in the end, all I used was the spring link! The switch sits in my spares drawer.

AzCal Retred · **Reply #18 on:** July 19, 2021, 03:12:35 pm

You are certainly right there. A big attraction is the stone simple nature of the Bullet. I am loath to abandon drum brakes & points/coil ignition, even the old-skool 4-speed Albion, but the solid-state rec/reg is light years ahead of the old mechanical voltage regulation, so it stays. LED's are bolt on stuff now and reduce electrical load on the Bullet charging system, so they have a place. Maybe tubeless tyres too, with proper rims that can still be laced with steel spokes. We are so fortunate to have a resource like Hitchcocks to make owning this dinosaur painless and affordable.

mrunderhill1975a · **Reply #19 on:** July 19, 2021, 08:08:54 pm

In my particular situation I am planning to upgrade the brake booster in my '89 jeep. I have been putting off the project as it requires a precise size of hole be drilled in the upgraded booster actuation shaft (the jeep has a strange brake switch that actuates when the pedal is pushed and the contacts engage by release of a spring pressure in the switch). The setup is difficult to describe, however, if the drilled hole is not correct by a few thousands, the brake light will either never come on or be perpetually on. With a proximity switch as backup, I can now proceed with my project knowing that if I make a mistake I could still recover by using a proximity switch setup. So, thanks again AzCal, I now have the confidence to proceed with my project knowing I have a backup plan.

Bilgemaster · **Reply #20 on:** July 20, 2021, 04:15:01 pm

Just to help sort of round out this "Brake Switchery Jiggery-Pokery" thread, I give you this dusty thread of yore with an easy fix for the FRONT brake switch at the lever, the one with the far too easily-broken securing plastic "bunny ears": https://forum.classicmotorworks.com/index.php?topic=26156.msg304614#msg304614

It's now been nearly three years, and what I'd first thought might just be a "temporary fix" is still hanging in there just fine.

"Takes this brother--May it serve you well."

Seipgam · **Reply #21 on:** July 20, 2021, 05:38:08 pm

I put a little self tapping screw in mine a couple of years ago, still holding fine.

I sure many of us have done a similar thing.

Geoff.

Mr_84 · **Reply #22 on:** July 20, 2021, 07:22:24 pm

Quote from: Bilgemaster on July 20, 2021, 04:15:01 pm

Just to help sort of round out this "Brake Switchery Jiggery-Pokery" thread, I give you this dusty thread of yore with an easy fix for the FRONT brake switch at the lever, the one with the far too easily-broken securing plastic "bunny ears": https://forum.classicmotorworks.com/index.php?topic=26156.msg304614#msg304614

It's now been nearly three years, and what I'd first thought might just be a "temporary fix" is still hanging in there just fine.

interesting I too had this problem I used a cable tie to hold it in place , then seen a new switch was only a couple of bucks so I brought a new one

Paul W · **Reply #23 on:** July 20, 2021, 08:54:14 pm

As my old building site foreman used to say, "A bodge that works isn't a bodge".

Mind you, those houses soon fell down