Epic MOT fail!

[Einarrson]

Well it's not that bad really.

1. Nearside front headlamp excessively deteriorated, light output severley reduced. <--probably just condensation.

2. Offside front headlamp excessively deteriorated, light output severley reduced. <--condensation

3. Nearside front position lamp (s) excessively deteriorated so that it is not visible from a reasonable distance.

4. Offside front headlamp aim is too high.

5. ABS warning lamp does not illuminate.  <-- Cause it's not there. I took it out and got away with it last time.

6. Offside indicator tell tale inoperative. <--change bulb.

7. offside hazard tell tale not working. <--change bulb.

8. Nearside brake cable has restricted free movement.

9. Offside brake cable has restricted free movement.

10. Front exaust sustem not adequately suppoorted < new mount.


The only one that is gonna be a real problem is the ABS. I've never been able to find the fault causing this, not even been able to get the front sensors out. Could removing the whole system be the best option? Basically the light doesn't go out, if that tells you anything.

So any ideas on what to do with the ABS would be greatly appreciated.

[melinx]

So any ideas on what to do with the ABS would be greatly appreciated.

http://totalcarlton.com/forums/index.php/topic,2394.msg24754.html#msg24754

[Einarrson]

Thanks Melinx I didn't see that one.

[melinx]

"When you're up to your arse in crocodiles it's difficult to remember that you were originally intending to drain the swamp" 

[Dave the Builder]

Best off sorting the lights and easy jobs BEFORE the MOT  
it's the first thing a tester checks.if they don't work the tester will look closely at everything.I do a pre mot check before test.
bosch headlamps have a chrome coating on the reflector that polishes up well, some other makes have a cr"" coating that oxydises and can't be polished back to life.
the ABS is worth fixing rather than hide the fault with tape or rigging time delay relays.

[Einarrson]

Haha is that a Chinese proverb Melinx?

To be honest Dave, I thought I had everything covered sorting the advisorys from last time. Suspension bushes etc...

Headlights never occured to me but I'm sure I have enough bits from other lights to sort the chrome. I think it's just condensation though. I'll take them apart and bring them inside to dry out.

Gonna ge the multimeter on the thing under the pasenger seat and check the ABS sensors asap.

[Dave the Builder]

When does the ABS light come on ? (if it had a bulb in )
after the car moves ? after you braake ? or just does not go off after the ignition power on self test ?

[carlton_mad]

probably the surge arrestor relay if its on all the time!! the last 3 digits are 794

[Einarrson]

Thanks for the replies in this time of minor crisis. The Carlton is my daily driver and I can't be without it due to work.

The light comes on for the test and stays on or at least it did when I had the bulb in last.

Before resorting to taking the bulb out I did try swapping the relays that I got from a VX scrapper, same numbers (thnx CM) can give that another try and I tried to disonnect the sensors bot the front ones are really solid.

I'm gonna try and measure the resistance across the sensors via the box under the passenger seat as mentioed in the link posted earlier in this thread. I take it you dont need to have the wheels turning to measure these values? Ingition on /engine running though?

[melinx]

http://www.topbuzz.co.uk/maintenance/testing_abs/testing_abs.htm

[Land-Barge]

For a tempory solution to the ABS problem you could wire the light up the oil pressure/alternator light.

[Dave the Builder]

For a tempory solution to the ABS problem you could wire the light up the oil pressure/alternator light.

As long as the MOT tester don't decide to test the brakes and see if they modulate (he only has to test by breaking hard 

[Einarrson]

Just tried to read the resistance from the ABS ECU plug.  Although the instructions of which pins to test seems vague you actually can't get it wrong if you count them right.

Trouble is I can't get any sensible readings.  A value will flash up for a second when you make the connection but every time you do the value is comptley different 4.6, 11.9, 16.3 etc...

I'm gonna try swapping the relays again.

The front disc guards are completely rotted so theres bound to be a lot of crud in there, maybe this is it?

[melinx]

Have you tried changing the polarity of the test leads over; the internals of the sensor have a solid state component in them which may be polarity sensitive

[Einarrson]

Ah no I haven't I'll give that a go.

[melinx]

Have you done this part of the Topbuzz test ? if you're on the verge of triggering the sensor, it may come up with a different reading each time

Just rotate the wheel/hub very gently and see if the reading jumps around as they suggest it should.

"With your DMM set to ohms, connect the probes to the connector, road speed sensor side (so it measures the sensor and not the ABS system). Take note of the value with the road wheel stationary. Now rotate the wheel hub and you should observe the resistance changing. It may not be a smooth transition, but it should change.

If the resistance value does change, then the sensor is OK. If it doesn't, then you may be looking at a new sensor, or there is a broken wire in the small amount of cable form leading to the sensor."

[Einarrson]

Ok I've just been outside spinning the wheels and there seems to be nothing coming out of the sensors.  When I connect I occasionally get a random 16. or 12. flash up but nothing apart from that.

The meter is a bit difficult to get into the plug so had to use a small drill bit but i'm confident it made the connection.

[melinx]

Remember that your DVM is very slow to react, which is why I said move the wheel very genty so that you're moving VERY slowly across the toothed wheel.

[Einarrson]

I can't turn them very fast as the brakes are a bit tight, though it's also hard to turn slowly with one hand while you hold the probes in with the other. I'll get someone to give me a hand.

[Dave the Builder]

If you have some fine multi stranded copper wire ,twist it round the test probes with the other ends stuffed in the multi plug terminals.... thus feeing both hands.
make sure you have the multi meter set to a sensitive range if it's selectable.

[Murph]

I've often heard it said that the job is much easier to do with an old type needle indicator meter.
They react much faster than digtal meters.

[DKT1]

Hi all, done mine last year. the two bits of wire stuffed in the plug/sensor end with terminal blocks on the other end connecting to the test leads is the best method of checking as you can put the meter on the floor and have two hands free.Yes you do have to turn the wheel slowly with a digital meter to see the pulses (No pulse it's dead) One of the first checks to do is from either wire to the sensor body/earth,to check that the internal coil is not shorting to earth as the main killer of these sensors is corrosion crushing the outer body onto the inner coil windings,you should have no reading/open circuit,if you do it's shorted.
you can't remove any of them without damaging them really unless your extremely patient and soak them for days and then they start to move but it takes hours of wiggling back and forth and flushing the corrosion out.
I only got one of the four out,the rear ones are the worst as the mounting bracket is aluminium and produces this white powdery corrosion,when you put WD40 on it it seems to clog it all together,if you give up and hack them out be careful as the brackets break really easily (I know I had to replace one) you have to place them across the top of the vice with jaws open and punch it down through the jaws,don't try to put one of the arms in the vice as one tap too hard and its gone!
After getting them all out trying to get replacements is a nightmare,you can get the fronts but no one stocks the rears,I got mine from here http://middlesextuninggarage.co.uk/ they stock them for the Lotus Carlton but only the fronts,so guess what, I've got two front ones fitted on the rear, just a small modification to the brackets and they work fine,the cables are a bit longer but that's what cable ties were made for!
Have tried two types of grease to stop the corrosion,have used hi temperature grease on the fronts to stop the rust/water penetration and used copper slip on the rears,checked them all this summer when I did a front to back suspension overhaul and they were all fine no corrosion,but will check the rears after this winter to see if it's still working or change it for the hi temp stuff.Oh I think they was about £28 each if I remember right, done all four so wont be doing that job again in a hurry.Hope that helps good luck!
(I went on a bit once I got started,didn't I)

[Land-Barge]

For a tempory solution to the ABS problem you could wire the light up the oil pressure/alternator light.

As long as the MOT tester don't decide to test the brakes and see if they modulate (he only has to test by breaking hard 

Never known a tester to do that other than test brake performance/balance on the rollers, must be a modern thing

Another thing if the headlights have condensation on the inside of the glass whack em on main beam for half an hour before test and it will evaporate

[melinx]

Another thing if the headlights have condensation on the inside of the glass whack em on main beam for half an hour before test and it will evaporate

I had a problem with condensation in the headlights on my previous Carlton; I removed the retaining clips cleaned them up and gave the seals a smear of Vaseline, it never happened again

[Einarrson]

Thanks DK. Yes I once tried to get them out of the front and it seemed pretty impossible.

OK so I did what was suggested with the wire and I wasn't getting anything but then I chaged the meter to 2000 instead of 20 and there seems to be a pretty regular fluctuation of the values when I turn the wheel slowly.

So, I will try the relay swap again assuming the replacement relays I have work?

How can you test the relay with the meter? Do you need the power probe to actuate the relay?