Discovery dipped lights will not switch off. Help please.

According to the wiring diagram in my Haynes manual the wiring is quite simple but the dip beam fuses are the fusable links then it's the light 'main & dipped switch and then the bulbs. Then there is your dim-dip relay and unit this uses the same fusable link and the power to the unit is via the ignition switch so if that's off then it's inactive.

So the main componants are the fuse, switch and dim-dip, so what happens when you switch to main been does the dip extinquish as it should on stay on.

You just need a 12v lamp and leads or a meter and with the circuit diagram test at each point of the lighting circuit.

Simples, when it's not raining

discool said:

According to the wiring diagram in my Haynes manual the wiring is quite simple but the dip beam fuses are the fusable links then it's the light 'main & dipped switch and then the bulbs. Then there is your dim-dip relay and unit this uses the same fusable link and the power to the unit is via the ignition switch so if that's off then it's inactive.

So the main componants are the fuse, switch and dim-dip, so what happens when you switch to main been does the dip extinquish as it should on stay on.

You just need a 12v lamp and leads or a meter and with the circuit diagram test at each point of the lighting circuit.

Simples, when it's not raining

Click to expand...

Removed the 3 relays in the pass footwell side panel ( still the lights stay on).
Re. so what happens when you switch to main been does the dip extinquish as it should on stay on..
When i switch the main beam on the dip light goes out.
When i switch the main beam off im back to the dip lights staying on..

That correct high beam or dipped beam one at a time.
So back to checking the light switches again.

discool said:

That correct high beam or dipped beam one at a time.
So back to checking the light switches again.

Click to expand...

Hi Again discool and thanks for your help and patience

I have removed the plugs from the light switch/stalk and the lights still stay on dip with them removed.

It's very difficult via a forum, but the next item is the dim-dip relay, for the 200's it's the black box clipped to the steering column so unplug that if you haven't already done so.
If still the same you will have to start removing fuses one by one to ID the circuit that's supplying the voltage.

I bet its the dim dip unit.

theres nothing else that could be supplying power to the lights!

Mr Noisy said:

I bet its the dim dip unit.

theres nothing else that could be supplying power to the lights!

Click to expand...

That's one bet you may win..hopefully for TMM. Now can I have some winning Loto numbers.. Please :tea:

discool said:

It's very difficult via a forum, but the next item is the dim-dip relay, for the 200's it's the black box clipped to the steering column so unplug that if you haven't already done so.
If still the same you will have to start removing fuses one by one to ID the circuit that's supplying the voltage.

Click to expand...

Hi Discool and Mr Noisy
I removed the black relay and they still the dipped lights stayed on. Is there a certain way or sequence to remove it? For example do i have to have the light switch on via the stalk before i remove the relay? or is it just a case of pulling it out and seeing if the lights go out? If its just a case of pulling it out and seeing if the lights go out i have done this and the lights stilll stay on.
To verify i have removed the correct relay! Is the relay the black one that is attached to the right of the steering column? this is 2 times bigger in lenth than the small yellow ones that are in the driver side foot well side panel?

Never seen it myself so can't say for sure.

However, if it is the right item, that's very odd.

You now need to get the test lamp and a circuit diagram out and start going through every option, to find out where that feed is coming from.

I thought the dim dip was wide and flat, but maybe that's just my imagination!

Mr Noisy said:

Never seen it myself so can't say for sure.

However, if it is the right item, that's very odd.

You now need to get the test lamp and a circuit diagram out and start going through every option, to find out where that feed is coming from.

I thought the dim dip was wide and flat, but maybe that's just my imagination!

Click to expand...

HI Mr Noisy

Have you got a link to the wiring diagram for the lights by any chance? i can't seem to find it in the rave manual

Re the relay, the only one that i can see that is attached to the steering column is black and long i will get a pic uploaded that might help to see if im on about the correct relay
i will have another look for a relay as you describe see what i can find.

In the Haynes manual the wiring diagram shows the dim-dip unit with five wires and discribes it's location as mounted to the rear of the steering column.
There is also a three wire change-over relay shown but the book seems to have missed out on it's discription.

The wires for the dim-dip unit are as follows:
white brown (oil pressure switch).
red (main light switch).
blue red (headlamp main & dipped beam switch and dipped beam).
blue white (headlamp main & dipped beam switch and main beam).
brown (12v supply).

Hope this helps.

Update

Finally found the relay and what a bugger that was to see, its tucked well up behind the dash and all i could see whas the connector plug, if it had not been for the wire colours i would probably never have known is was there .
I removed the relay and the lights work great now :biggrin1
Although i do have a concern regarding the other things that this relay connects to like the (white brown (oil pressure switch).
red (main light switch).
Will it be ok to use the discovery without the relay or do you recommend buy a new one ?
I would like to say a big thanks to everyone who replyed in the topic and a bigger thanks to Discool and Mr Noisy your stars :biggrin1::tea:

You don't need the dim-dip so if you side lights, main and dipped beams are ok leave it disconnected, the connection to the oil pressure switch was to tell the unit the engine was or was not running via an earth return, as you know dim-dip only works when the side lights are on and the engine is running.

The 300 series D-D is slightly different in that it has a resistor on the engine bulkhead I pulled the plug on mine as I have LED side lights which look a bit naff when the D-D was on.

discool said:

You don't need the dim-dip so if you side lights, main and dipped beams are ok leave it disconnected, the connection to the oil pressure switch was to tell the unit the engine was or was not running via an earth return, as you know dim-dip only works when the side lights are on and the engine is running.

The 300 series D-D is slightly different in that it has a resistor on the engine bulkhead I pulled the plug on mine as I have LED side lights which look a bit naff when the D-D was on.

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Hi Discool again.
Thanks for the info once again as i have already said you should have a mod position on the forum here for all the help you give to people :clap2:
By the way my side lights actually work without the engine running

TMM said:

Hi Discool again.
:clap2:
By the way my side lights actually work without the engine not running

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Parking Lights .... they should be called only that.

It's best to park the car with the engine stopped and the key out!

CharlesY

TMM said:

Hi Discool again.
Thanks for the info once again as i have already said you should have a mod position on the forum here for all the help you give to people :clap2:
By the way my side lights actually work without the engine running

Click to expand...

That's correct TMM, they all do but a dim-dim system dosen't.

CharlesY said:

Parking Lights .... they should be called only that.

It's best to park the car with the engine stopped and the key out!

CharlesY

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There's no requirement now to park cars in a built up areas with lights on or an o/s light light showing as required years ago.
They are called side lights I use them as that at dusk and sometimes in bult up areas when there's not a reason to use dipped head lights.

discool said:

There's no requirement now to park cars in a built up areas with lights on or an o/s light light showing as required years ago.
They are called side lights I use them as that at dusk and sometimes in bult up areas when there's not a reason to use dipped head lights.

Click to expand...

Thanks Discool you have been a brilliant help yet again to me.
I appreciate the time you take to help me and other people your a star
raise:

The winning lottery numbers for you this week are. 12, 18, 29, 33, 41, 46

discool said:

There's no requirement now to park cars in a built up areas with lights on or an o/s light light showing as required years ago.
They are called side lights I use them as that at dusk and sometimes in bult up areas when there's not a reason to use dipped head lights.

Click to expand...

If it is after "lighting up" time, that might be unlawful.

CharlesY

Thanks TMM for your appreciation, allow me to explain!

Actually chaps, they should be called position lights. They are for use when you want/need to display the vehicles position on the road without actually needing lighting to see with.

When the disco was made, it was decided that the position lights alone were not sufficiently bright enough to make the car stand out in low light conditions, so a dim-dip system was fitted.

This system illuminates the dipped beam lamps to something like 1/4 brightness when the position lamps are switched on and the engine is running.

Thus, if the vehicle is parked, only the position lights are used. If the vehicle is driving, the dipped beams are illuminated dimly also, for more visibility on the road (not to see with)

TMM, you will notice that switching to dipped beam on the stalk significantly brightens the dipped beam lamps when the engine is running (obviously when your dim dip is working properly!)

For some reason it is no longer a requirement for certain cars to have a dim dip function, so it is not necessary for it to be working anymore.

If mine stopped working i would replace the relay because i quite like the old fashioned quirks about the car.

Hope that helps!

Cheers, Sam.