Brake light switch renewal/ABS light on now!!!

[flyin2wheeler]

So,had the car at MOT(northren irish MOT) and brake lights....nada!
so,inspector gave me the mot on condition i sort the brake lights.
went home,took switch out(which is a fecker to get to),stripped it out,cleaned it up and refitted and brake lights are working but....
now the dam abs light is on!
How is that possible with a switch clean refit?
I did have some water ingress in the drivers foot well,usual story,damp block connectors so i cleaned and dried all out.
Have checked resistance on all 4 abs sensors and all ok,relucter rings look fine,all fuses grand too...light hasnt went away!
Any thoughts?

[steve_earwig]

Feck knows, coincidence?

Did you take it for a drive?

[flyin2wheeler]

This cars at some stupid sh*t!
Yip,drove the car still the same and..wait for it..bleepers go off,stop light comes on!!
Obviously an electrical gremmie so trying the ECU reset tonight.
If that fails..diagnosticstime!

[GingerMagic]

Have you got cruise control? I'm just wondering if the cruise switch isn't in sync with the brake switch and flagging a fault.
Just a guess, sorry...

[steve_earwig]

Usually the BSI flags up a coherance issue and cruise doesn't work, no ABS fault is flagged.

Yip,drove the car still the same and..wait for it..bleepers go off,stop light comes on!!

Whuh? Bleepers? STOP light on the dash?

[steve_earwig]

Any chance you've pulled on something you oughtn't while you were changing the switch?

The abs sensor feeds do go through a connector in the footwell (not sure where you measured them from, ignore if it was from the connector on the abs unit)

[flyin2wheeler]

is the connector in the footwell for the abs a black one with a red slider which seperates it and maybe 12 wires?
I measured each sensor with the ohm meter where they plug in( 2 near diesel tank,2 on strut tops) and i dont have cruise control.
Wondering if maybe the system detects a voltage drop on brake light switch as i didnt renew it,i just pulled it apart,cleaned,refit.
also...the black red connector in the footwell,i cleaned all contacts in there by scraping them with a sharp flat screw driver,could i have shorted something in there by doing that?(still had battery connected when i did it and starting to suspect i shorted a component).
Going out soon now to hook up the battery to see if its reset itself and yes..the stop light coming on was weird although car had no issues,it didnt go into limp,temp was grand and no nasty noises,weird one alright.
The car itself is the 04 hdiS model.no cruise

Just rehooked up the car battery after it being off all night..it has achieved nothing.
abs light still on and it even threw up an airbag light too but this has now disappeared..french electrics!!!

[GingerMagic]

I had an ABS fault recently, if I ignored it and carried on driving then my 'SYOP' light came on with a bum clenching beep beep...
I ignored it and the problem went away - bad wiring on nsr sensor...

Not sure what to suggest, that hasn't been suggested already...

[steve_earwig]

16 way black apparently, not sure about the red bit but that's probably not important. Did you do this the same time you did the brake switch or was it ok for a while?

Most components and connectors are made by either Siemens or Bosch - German electrics!

[flyin2wheeler]

16 way black apparently, not sure about the red bit but that's probably not important. Did you do this the same time you did the brake switch or was it ok for a while?

Yip,thats the one..so the ABS works via that plug then?

Yes,when i was fixing the switch,i looked at that plug as it had gave issues before,wet and cruddy looking so then i scraped all the crud off with a screwdriver,dried it out with the air line,possiblly shorted it when in there with the screwdriver and blew a senser out although the readings say otherwise from the multi meter,in round the 1.5 ohms for all.
Until I touched the brake switch,it hadnt the abs light on..and now it does.
Looking like a diagnostic check on a PC.
Also,it had the EML on for the past few months..and guess what..its disappeared now!!

[steve_earwig]

Looks like just the rear sensors go through it (as well as a shed load of other stuff).

[flyin2wheeler]

Looks like just the rear sensors go through it (as well as a shed load of other stuff).

It definetley feeds the rear lights too.had issues with rear lights and that plug before