ABS problem on a 94 Diamond estate 2.0L

[DiamondDriver]

Help please with ABS problem on a 94 Diamond estate 2.0L

The abs dash light comes on within a few yards of driving.  (Previous couple of years it used to come on anytime between 1 and 100 miles).

I have jacked up the rear wheels one at a time and spun the wheels fast with the engine and no light comes on.
I jacked up the front wheels one at a time and spun the wheels by hand (and foot) and nearside front caused the light to come on.  Although the N/S front sensor gave a reading of 1600 ohms like the offside one I fitted a new sensor anyway (£££ ouch!) but it is just the same.
The digital multimeter flashes readings between 1300 and 1900 ohms when the wheel is turned.
I assume from above all the wheel sensors are working correctly.

I also of course swapped the relay in the black box near the bulkhead and the 2 relays in the black box under the power steering reservoir BUT THESE WERE FROM A SCRAPPY so possibly faulty?

Any ideas of what is at fault?
If a relay is suggested has anyone a good set I could try?  And no I will not send you back a dud which I believe has happened in the past (some people!!)

MOT runs out today and ABS problem needs sorting (along with reversing lights if these are a fail?) before I can book another MOT test.  Otherwise the scrap yard will get a call or perhaps member colc would be interested in saving the old girl?  Some of you will have seen the car a couple of times at Billing, it is Rembrandt Silver in colour, manual, black leather and resides in St Neots.

[Whippit]

Cracked Toothed ring on the offending wheel

[Dave the Builder]

Cracked Toothed ring on the offending wheel

the teeth may just be crudded up with grease/brake dust, worth checking.
the toothed cog could be cleaned with brake cleaner and a straw if you struggle to get at it. (some pound shops do brake cleaner aerosol cans and you can use the straw from wd40 to direct the spray)

reversing lights are not part of the mot 
depending on the mot tester.... some pass the brakes anyway as long as they stop the car with good readings  allegedly ,other tricks include sticking black tape over the warning light or removing the bulb  not me Guv 

[Whippit]

Reading his other posts he is getting judder on braking.
This is classic for a missing tooth or broken ring.
Could be crud but it would have to be magnetic.

Best way to get it through MOT is to remove the ABS fuse and take out the bulb (the ABS will be disabled so no judder)
However if its an auto this will cause the gearbox to go into limp mode as its on the same circuit (Guess who has had this problem LOL)

[Dave the Builder]

I bow to your greater knollege on this,I only had my auto about 2 weeks 
Is it the ABS causing the judder ? 
could it be a distorted disc or wheel bearing u/s 

[DiamondDriver]

Thanks for your ideas.

However no brake judder for about 4 years when ABS played up for a while.  Soon after changed discs etc and they are still good.

The rear rings are obvious to me.
This ring I assume will be on the front nearside but I cannot find anything anywhere about it in Haynes.  Is it attached to the disc?   If I took the wheel sensor out would I be able to clean the ring through the hole?

[carlton_mad]

the fronts are on the hub itself i have a couple here for sale if required (complete units)

[Dave the Builder]

   If I took the wheel sensor out would I be able to clean the ring through the hole?

I'd advise you don't remove the sensor unless you have too, they break very easy.
photo of hub showing teeth

[DiamondDriver]

Yes it is all very straightforward in theory now that I have seen the picture.  Just depends whether I can actually undo that nut and get the hub off the shaft in reality.

As that brand new ABS sensor will come out easily I shall attempt a clean first and if that fails I will be in touch with Mr Mad regarding a hub.

Thanks for your help everyone.