MOT time and guess what - the brake lights don’t work. - Bulbs are OK. - No voltage at bulb terminals when ignition on and pedal depressed. - Voltage is Ok at both pressure switch plugs when ignition on. - Forward switch resistance drops from 24MOhms to 13MOhms when brake pedal pressed. - Aft switch resistance drops from 14MOhms to 0.3MOhms when brake pedal pressed. 1) The forward switch has probably failed but is the aft switch resistance also too high? 2) If the aft switch is OK, shouldn’t it still be able to operate the brake lights on its own? 3) I want to try bypassing each switch to confirm that the rest of the wiring is Ok. I now know which of the 3 pins comes from the fuse but does anyone know which pin goes to the brake lights? Is it the one that sits opposite (and parallel to) the fuse pin in each case? 4) Who’s the best supplier of good brake light switches? Thanks.
I couldn't find any decent switches but decided to carry a spare - only a fiver ... Sent from my SM-G960F using Tapatalk
I bought a pair of ATE 3pin switches from Auto-Doc a while ago, fitted them recently because the ERA one's i had on started to occasionally need excessive pressure to work. I would never have known about the problem without the third brake light I've fitted at the bottom of the rear screen. LED brake lights help as they need far less juice to work, reducing the load on the contacts in the 'marginal' b/switches. Top Tip , don't buy cheap ones.
Two ATA 3 pin switches on order. Just need to confirm that the rest of the wiring is Ok tomorrow. Thanks all.
