strawboss

Infamous Brake Switch

39 posts in this topic

I'm all caught up with the truck so on to the new brakelight switch, the hole in the bracket needs to be opened up by a millimeter, the fit looks good, the plunger will have a serious rubber boot on it when mounted.post-6231-1405636850_thumb.jpgSince I will be doing other things I thought I would get all four wheels up as high as possible.....wish I had a hoist!(In picture #1 there is a chock under the front driver's wheel it just doesn't show too well!)post-6231-1405636993_thumb.jpgpost-6231-1405637006_thumb.jpgTime for supper.....

Edited by strawboss

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can this brake switch cause the esp light to come on then the transmission gets confused? rough clutch operation and finally 3 bars? not only in cold. I have had this happen a couple of times. shutting down are restarting and it is ok. I have never changed mine and wondering if I should look into. I do not have any stored codes, it is all 'check marks' on Andrew Lee's (Lee's AutoHaus) diagnostic unit.

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In my experience a bad switch shuts down the ABS & ESP systems ( with the appropriate warning lights) and the "hill holder" feature doesn't function but the switch only starts malfunctioning in cold weather (in my case under -10 Deg Centigrade ) since I have a "new & improved" version of this switch. 3 bars can happen for a number of reasons but I would make sure your battery is healthy to start with since so many functions depend on it.

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I have the new brake light switch installed with a small magnetic reed switch to act as a brake position indicator to the SAM.I cannibalized the old OE switch to use the plug contacts and think the 1/2 mm gap between the low current signal terminals & the high current terminals of the brake light switch light switch may explain the OE switch's sensitivity to moisture and freezing temps.......soldering the new leads to the back of the plug was "challenging" :rolleyes:post-6231-1405733336_thumb.jpghere is my"hot rod" switch installed, the reed switch is just peeking out above it and to the right of the white bracket holding the actuating magnet.....post-6231-1405733544_thumb.jpgThis is a different perspective before the reed switch was installedpost-6231-1405733738_thumb.jpgTesting it tommorrow.Oh, and the plastic cover does fit (barely) over the new switch.....

Edited by strawboss

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Well, my mod passed the "smoke test". No idiot lights on,so the SAM seems none the wiser to the changes.....the acid test will be the first cold day in December. :D

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The car is now back to stock as the mod needs more adjusting. The issue seems to be the timing of the "signal switch" actuation to the brake light switch actuation, I realized going in this may be an issue & was right.The abs/esp lights would come on after varying amounts of time along with the "3 bars" signal on the speedo/shift indicator, oddly this did not prevent gear selection or general operation.....I just had to guess what gear I was in.I frigged around with different power magnets and types of reed switches as well as adjusting the sensitivity of the brakelight switch proper but no joy, sometimes the gear shift indicator would work but the abs/esp system wouldn't or vice versa, I couldn't get both systems and/or the SAM to be happy with my jury rigged pair of switches. Drat.

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Yes, sequence of switching must be right or your Smart will play up. Easiest and cheapest solution for superior brake light switch is the design suggested in post 2 in my humble opinion.

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I went to the junk yard and found an unmolested brake pedal assembly to replace the one I had "modified"....installed it in August with the original OE switch as designed by smart/mercedes and if needed would wire a relay "a'la tolsen".....turns out this assembly would not behave the way the original did in Arctic temperatures,,,,wtf??Can't explain why.....but I didn't lose the abs/esp systems once all winter!

It will be replaced by my Mirage in a few days,I will be sort of sorry to see it gone .....

Edited by strawboss

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Ya, As much as I have enjoyed it I figure it was time for a change....the original plan was to sell my Tacoma & the smart at the same time and buy a Diesel Colorado Pickup but the EPA has turned any recent Diesel vehicle into a maintenance nightmare, what with particulate filters and DEF not to mention the egr valves.... :icon_rolleyes: so I'll keep the Tacoma for the country and run the Mirage in the city.

I won't be as "eccentric" (my neighbour has said) but I should have more time for fishing etc....

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You can never spend enough time fishing. I'll be keeping my Cabrio until I expire. Got my bus pass a couple of months ago so not really dependant on a car any more. Enjoy free bus rides all over the British Isles. Most have also free broadband so I can log on to Clubsmartcar.

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ive learned to wet my brake arm with antifreeze this time of year...just enough to run down to the switch....i just wet a paper towel and squeeze it out enough to run down into the boot

 

ive done it to my friend smart too....it has completely stopped the annoying "winter freeze up" of switches on both cars

 

no noticeable side effects yet

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yes...just regular car antifreeze...why?..is there something i should know?..will it blow up or something?...my brake switch problems were always due to snow melting off boots and freezing up the switch

 

first time i removed the underpanels and opened up the protective box (in -30c weather i might add)....used heat gun to melt and dry it out ,,then got the idea for antifreeze after deciding i didnt want to be doing that again (even thought about mounting a bulb in there on a switch to warm up the box)

Edited by LooseLugNuts

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