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GSA front brake switch

Posted: Sat May 04, 2019 7:16 am
by flipflopdog
Gents, any bmw techs reading this or GS boffins please can someone shed some light on this issue. …….( I am using GSA switchgear and levers on my special build) .........As a sparky for many years and have worked on automation etc etc I know a thing or two but what I want is confirmation from others that there IS or there ISN'T a switch that I can use in this situation. Please see the attached pic showing part number 10 (61317671111). This little chap is a N/O switch that is held closed when in the normally installed position and the lever at rest. Actuate the front brake and the switch opens. This I found out after installing the very expensive little barsteward, basically the brake light is on all the time and goes off when you apply front brake, totally the opposite desired effect...!!!

I can only deduce that this switch is designed to operate with the ABS module in some way and the ECU then gives a positive voltage to the brake light circuit. SO, what I want/need is a switch to plug straight in that has the opposite config (ie: N/C and opens when installed in the compressed state). Anyone..????

NB: I have gone through the entire OEM bmw catalogue on the GS range to no avail and haven't got it in me to search all other models so if anyone on here can help then brilliant.....
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Screenshot (314).png (151.93 KiB) Viewed 3010 times

Re: GSA front brake switch

Posted: Sat May 04, 2019 9:09 am
by dunny
You could get around this by installing a 5 pin relay ?

Re: GSA front brake switch

Posted: Sat May 04, 2019 3:29 pm
by sledgegreen
Would a change-over relay help?

https://www.autoelectricsupplies.co.uk/ ... ategory/36

These have two outputs, and the relay flips between them so one of them is always live. Use the output from your expensive bar steward switch to trigger the relay, then attach the feed to your brake lights to the relay output which is live when the lever is pulled. Leave the other output unused.

Re: GSA front brake switch

Posted: Sat May 04, 2019 7:12 pm
by Dark Knight
Sounds like sledgegreen has the best idea, a small relay suitably rated for the current that it is switching would be pretty cheap on Ebay or similar.
You just have to find somewhere to fit it.

Re: GSA front brake switch

Posted: Sat May 04, 2019 10:38 pm
by sledgegreen
Unfortunately, I currently have much more familiarity with the AES website than I really want. This is not their fault ...

I have an old Landrover, which is currently undergoing a gradual rewire. It seems that 40yrs is the maximum lifetime for 1979 LandRover wiring. Every couple of weeks, a circuit dies and I have to trace out that circuit, and replace it. This is complicated because it is ex-army, and the military seem to like complexity - it has a military light switch, which has six positions - on and off, as normal, plus 4 positions which enable or disable various combinations of lights for driving in convoys etc. Then there is a separate switch for driving on infra-red headlights. The IR headlights are in fact a couple of plastic filters which clip on to the headlights, and the driver then has to wear IR goggles. The "IR Headlight" Switch actually disables all external lights except the headlamps, so that no squaddy can accidentally switch on the hazard lights whilst they are trying to sneak though the Moscow suburbs, which might be embarrassing.

About 3 weeks ago, the Landy broke down. I quickly realised that one of the wires on the coil had broken at the point where the female terminal was crimped on at the end where that wire attached to the coil. As soon as I touched it, the other end of the wire broke free of its terminal. That's how fragile some of the wiring is.

Incidentally, I highly recommend AES. I have used them many times over the last few months. No problems at all - everything ordered has arrived in a few days, all charges have been correct. No hassle at all.

Re: GSA front brake switch

Posted: Sun May 05, 2019 11:46 am
by flipflopdog
I've pondered over using a relay but if you saw how many relays I already have to make the CANbus switch clusters work in conjunction with the 25 year old K75 wiring system then you'd understand why I'm pushing for a retro fitment scenario ….

Re: GSA front brake switch

Posted: Fri May 10, 2019 4:29 pm
by Britmech
use a banjo bolt pressure switch !

Re: GSA front brake switch

Posted: Fri May 10, 2019 4:46 pm
by bowber
sledgegreen wrote: Sat May 04, 2019 3:29 pm Would a change-over relay help?

https://www.autoelectricsupplies.co.uk/ ... ategory/36

These have two outputs, and the relay flips between them so one of them is always live. Use the output from your expensive bar steward switch to trigger the relay, then attach the feed to your brake lights to the relay output which is live when the lever is pulled. Leave the other output unused.
I think I'll have to put my son onto that website, he too has an ex army Land Rover 110, and it also has the rotary light switch.
He's just in the process of adding a few modern luxuries such as charge points for his phone and satnav etc.

I'd suggest a banjo bolt switch too, they are usually very reliable and have the advantage that the brake light only comes on when actual pressure is applied to the brake system, rather than a badly adjusted switch flickering on and off.

Steve