mk2 full beam blue light..

[chrisdevon]

A Problem very similar to other thread below by hanna.melbo
but different.
When I flash lights or use full beam when driving the blue light does not come on, but the rev counter dies, whilst on full beam.
that's fine but its an MOT failure it seems.

Odd thing is oil pressure light flickers too at same time.

However with ignition off, if I flash my lights the blue light does come on, so its not the bulb.
But to test with lights on I have to turn ignition on, and so again doesn't work, or with engine running, the rev counter drops.

any ideas? I can't find the brown cable referred to in other link. I have had the speedo/dash out three times fixing the odometer, so may have upset something.

Many thanks, fingers crossed Chris..

[steve bain]

there is an earth (thin brown) cable which connects to the rear right of the rocker cover. check that hasn't snapped. if it does it creates havoc with your dials etc.

[chrisdevon]

Cant find that brown cable, its not connected to rocker any more, could you let me know where it comes from? so I might find the other end, may have been snipped or just dangling, engine was replaced back along.
That said have a feeling my meddling with the instrument cluster to fix odometer may have caused this, not 100% sure.

car electrikery....not my favourite.

[mark1gls]

Not the best pictures but you can see the brown wire fixed to one of the rocker cover studs just above the oil pressure sensor.
There is a bracket which it fits to but it yours in missing or not still attached to the wire you can fix it to the stud, the other end of the thin brown wire is with the oil pressure sender and a couple of other wires (can't remember what else is with it) coming out of the black plastic protective cover near the servo and master cylinder.

If you click on the picture it should make it bigger.



You should also have an bigger earth cable from the same stud to the bracket of the coil.

I think it's only car with the MFA in the dash which have the thin brown wire but not 100% sure?

[steve bain]

ah. i have an MFA in mine so may be giving you duff information.

[chrisdevon]

thanks for photos, but if MFA is the computer thing, I don't have it, just a digital clock..
That said about coil earth strap, on switching the ignition on, the rev counter jumps up to 2k revs and drops down again before I even turn the key. So wonder if there is a connection with my issue and earthing, coil etc.. mmm.