No brake lights/cruise control

[Dodger1855]

Hi, hope someone has a fix for this issue with my 2001 SLK320.
Problem started with BAS/ASP warning light coming on when braking, it goes out when I switch off and start again. I then noticed Cruise wasn't working (it's OK if I start and run without touching brake pedal) I was then 'advised' by a following truck that none of my brake lights are working.
I went for the obvious and have fitted a new switch but this hasn't changed anything (glad they are only £14.20)
Has anybody come across this before?
Regards, Roger

 

[EmilysDad]

.....
I went for the obvious and have fitted a new switch but this hasn't changed anything (glad they are only £14.20) ....

..... and adjusted correctly?

 

[television]

Is the ABS lamp on

 

[Dodger1855]

Thanks for the replies.

..... and adjusted correctly?
as per manual: hold pedal down, fit switch, release pedal to self adjust.

Is the ABS lamp on?
No, but have had an intermittent bulb out warning on the O/S brake light, new bulb holder seemed to fix this.

 

[television]

It is an odd one if a new switch has been fitted and the correct one, you are missing or have a faulty component that is taking out the speed signal, If the old brake switch had a problem it may have taken out a fuse for a BAS ESP component.

 

[Dodger1855]

Just got some time back on the car, have checked all the fuses and they are OK.
Can't understand how a dead speed sensor would take out the brake lights, looks like it's a trip to the sparks for a diagnostic.

 

[television]

Something has happened, and we do not know what, its the third car within a few days where this has happened. The brake lamp circuit has nothing to do with any speed signal

 

[Dodger1855]

OK, so I am looking at two separate faults, that makes sense. Weather permitting I should get some time to check the brake circuit over then have a look at the speed sensors. Will post back if I find anything, updates on the two other cars would be useful, can the threads be linked?
Thanks again, Roger

 

[television]

Most cars have a fuse for the brake lamp, I have not checked yet on this car. Mercedes use a live feed on the brake lamp, this provides the live plus 12v to the lamps

 

[penton]

Check the new switch. From memory one pair of contacts makes and one pair breaks a circuit. I bought a switch which was faulty from new and had to exchange.

Robin

 

[Dodger1855]

SUCCESS!! I have brake lights again!!!
Used Ohm tester and traced a broken wire to brake switch (black/white) in loom above pedal assembly, cut it out and soldered in a new length.
Just leaves BAS/ASP fault to work out.

Thanks to all for assistance, Roger

 

[television]

SUCCESS!! I have brake lights again!!!
Used Ohm tester and traced a broken wire to brake switch (black/white) in loom above pedal assembly, cut it out and soldered in a new length.
Just leaves BAS/ASP fault to work out.

Thanks to all for assistance, Roger

Could be broken wires for this fault as well

 

[Dodger1855]

:lol:
OK, here's the thing, all is normal.
Since the dash was part stripped I figured might as well replace the speedo light that had blown. Now I know this disturbed the looms behind the dash and tracing the broken wire from back light to front of car will have jiggled stuff around but since I had brake lights again I though it was time to go play in the snow.
Started car and drove out of garage to (drum roll please) no warning lights!!!!!!!!!!!!!!!!!!!!

Hope someone with more electrical knowledge than me can figure that out while I go power sliding in the powder!

Once again huge thanks to all. Roger

 

[television]

We often never know why some faults just appear,, then they can go away never to be seen again, The BAS thing is or was a CAN problem, sometimes these things do self correct, driving the car will prove the point.

There will be a fault code stored, that can stay there, when you have the car serviced ask them to check to see what it was if it all drives fine