Brake Warning Light - Mod to use a Buzzer?

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Bay_Buster

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Hello all! So I've been up late a few nights in a row researching bits, getting my head around the various systems/parts/etc that I need to fully understand before the van gets painted so I hopefully don't find out I need to alter something/weld something somewhere etc afterwards :shock:

The latest voyage of discovery was the braking system. I've had a copy of a 68/69 wiring diagram for years (only just noticed it's an American spec diagram, VWoA) and have been comparing what I've found out about the brake light switches/warning light circuit to that.

So, if my research is correct, UK model early bays never had a 'Brake Warning Light' fitted as standard, just two 2-pin pressure switches wired in parallel to operate the brake lights on the rear of the van. This matches my dashboard cluster, as mine doesn't have a brake warning light, or even the moulding in the plastic for one. However later vans and the American spec ones apparently do have a brake warning light... such as the one circled below...



And this one is the same as my dash cluster, no brake warning light:



The very early vans using a brake warning light used a special (68 only?) master brake cylinder, with a mechanical plunger that operated a separate push-to-make type switch that switched the brake warning light should one of the brake circuits fail. Both these bits are now obsolete and unobtainium from what I've read. I've circled the switches of interest and the dashboard brake warning light in pink on the chunk of wiring diagram below. The unobtainable brake warning switch is circled in pink with a score through:



The later vans just use two 3-pin pressure switches to achieve the same thing, with much more simplicity, as per these schematics below (I think I nabbed them off this forum, but I can't remember, it was late sorry :| )







Soooo where is this going? Well, seems to me that it's a sensible idea to have some sort of warning system if a brake circuit fails, or even if one of the switches fails (probably more likely). I don't want to drill holes in my original dash cluster, or metal dash, to fit a genuine brake warning light. I also don't want to change out my dash cluster plastic for one already fitted with a brake warning light. It's not right for my early RHD UK spec, and more to the point I think the lights look a bit naff! So I was thinking of following the 3-pin pressure switches schematics above, but instead of wiring in a warning light I could easily hide a miniature 12V buzzer in the dash void somewhere. Something like this...



Only a few quid on ebay, quoted as being a continuous 400Hz tone at 80dB (there's lots at 90dB but I recon that will be a bit loud up close).

What are peoples thoughts on this? Anyone heard of anybody doing anything similar? No extra pressure switches required, just two 3-pin ones instead of 2-pin ones, pay a few quid for a buzzer, and run a few more wires. Seems a nice simple, cheap, and undetectable mod in my brain (until the buzzer sounds of course) but I am very tired right now! I'd love to hear peoples thoughts.
 

67panel

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It would work, thing is by the time the buzzer works you will have lost a circuit already and pedal will nearly go to the floor so its a bit stable door to my mind.
 

Bay_Buster

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Yes, I did think of that, but if a pressure switch fails you wouldn't know whilst the remaining good pressure switch operates the rear brake lights. Then possibly your other switch goes bad, and then you have no working brake lights without any clue until someone slams into the back of you?! I see this scenario being more likely, and a warning being very useful?
 

mike202

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my view on this is that if you keep the brakes maintained and check the fluid level regularly the 'warning' light is unnecessary. As said above you will soon know if your brakes are failing before the warning light or buzzer comes on.
 

Coda

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Well, brakes DO fail, though rarely. What the value in having a light or buzzer is, is that you may find out with enough warning (i.e. right before you need them, instead of right when you need them) giving you enough time to bring the bus to a halt and avoiding a collision.
 

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