Brake light problem

Brake light problem

Author
Discussion

MarkS4

Original Poster:

51 posts

220 months

Friday 11th October 2019
quotequote all
My S4 has just failed its MoT because the brake lights are not working. The garage reckons the problem is the pedal switch. Their usual supplier can't help. Any suggestions would be welcome.

Mark P.

GreenV8S

30,150 posts

283 months

Friday 11th October 2019
quotequote all
As far as I remember it's a generic switch. Take the broken one to a local motor factor and ask them to match it.

Adrian@

4,290 posts

281 months

Friday 11th October 2019
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Lucas SMB 421, if has burst through once it will need adjusting too (it will not come with the 1/2 inch ID spacer/packer washers and 1/2UNF anti rattle washer and half-nut though, BUT you should be able to use the old ones). A@



Edited by Adrian@ on Friday 11th October 17:06

Blue 30

519 posts

116 months

Friday 11th October 2019
quotequote all
Just for your own satisfaction, and before you go buying a new switch.
Turn ignition on.
Remove both wires from the switch, and touch them together.
Get a friend to confirm that the brake lights are coming on.
If they do, it confirms the switch is faulty.
If they don't, you'll need to do some more testing.
Because you have a further problem.
T.

phillpot

17,105 posts

182 months

Friday 11th October 2019
quotequote all

Switch is common to Land Rover and Mini, cheap as chips


v8s4me

7,234 posts

218 months

Friday 11th October 2019
quotequote all
If the switch is OK then look at the crappy light cluster connectors in the boot. They are notorious for poor connections.