I've just bought a 1997 Disco 1 in Canada and I've noticed an odd symptom (I'm not sure it's even a problem) .....

When I start the engine, after a short (10 seconds) delay, the Main/High Beam warning light comes on dimly. When I turn the lights on (side or head), the warning light goes out, until I put the lights on Main Beam, when it comes on at full power. If I turn the headlights off, leaving sidelights on, the Main Beam warning lamp glows dimly. It extinguishes after I switch off the ignition. All the lights appear to work OK.

I don't think it does this all the time, which is why I think it might be some kind of fault indication. I've observed the same symptoms on other Discos of the same age, so I'm hoping that someone out there has seen it before and knows what it is. I'm not too concerned about it, but it just doesn't seem right, so I'd like to get to the bottom of it.

My Discovery has the Canadian Daylight Running Lights option - I don't know if that has anything to do with this ....

Thanks in advance to anyone responding ....

Axxell

Had a look in Rave (Suite of manuals for LR) and the main beam warning light should only come on when High Beam is on, so I'd say there's a fault ... possibly a short at the headlamp connectors, I've had a few faults when it's been stood and corrosion has occurred but not this one ..

I'd basically just check the bulbs, their connections and connectors and associated wiring .. look for chafed wires, rust, crap, broken wires etc etc ..

In all my Discos, newest of which has been a 94, the main beam has also lit dimly when a lowbeam headlamp bulb has had a problem, either failed completely or as in the current one just alittle dim due to bad connection.

Not sure its an intentional desgin feature, but certainly a consistent one in my experience

I would check the condition of the 3pin headlight bulb plugs, the ones on the back of the bulbs.
They are prone to overheating with the result that the plastic melts and so creat either a bad connection/short or a bad earth connection. Your car is about the age when this problem seems to occur.
I would also check the condition of the headlight eart connection onto the inner wing, one each side of the car. They may be corroded. Disconnect , clean all surfaces to bright metal and reassemble. Coat with grease to stop the air getting to them.
The orther thing worth checking is the main body earth connection, located behind the battery on top of the inner wing, looks like a cable clamp on the main negative (black) cable from the battwery -ve terminal. Again, disconnect, cleanto bright metal and reassemble.

The blue high beam warning lamp is powered by the same fuse as the RH head lamp (F4 high beam fuse) the lamp then terminates to an earth possibly at one of the earth points behind the footwell kick panels, there's no other connections unless your wiring has been modified that is.

Maybe because of poor head lamp earthing due to corrosion the head lamp is partially earthing it's self via the warning lamp earth connection.

So as Paul D (who has a suite of Rave manuals) said above, check the connections

discool said:

So as Paul D (who has a suite of Rave manuals) said above, check the connections

Click to expand...

Cnut

bulb problem, with my disco when this happend. new bulbs sorted it for me

After a lot of checking connectors, replacing bulbs and measuring voltage drops, I've come to the conclusion that this is a design feature.

I had a couple of late 80s Range Rovers in the UK which had a "Dim-Dip" feature which turned on dip beam headlamps at reduced intensity whenever the engine was running (presumably to attract more Volvo devotees to buy Range Rovers ?) The actual electronics were a piece of Lucas crap which was prone to frequent failure which tended to leave you with headlamps which wouldn't turn off under any circumstances - and the module was horribly expensive to replace. I think they discontinued this stupid idea after a couple of years.

In true Canadian style, all vehicles sold over here were fitted with an even more poorly conceived version of this crappy idea, known as Daytime Running Lights. In this implementation, whenever the engine is running, the headlights are turned on at reduced intensity but, in this case, on main beam. Consequently, the Main Beam warning lamp comes on at reduced intensity whenever the engine is running. What a great feature ! At least the control module is no longer manufactured by Lucas - it can't be; I've had the Disco for over three months now and it hasn't failed yet !

Pretty sure you'll find that's a poor earth either in or to the cluster.
Have you got Rave and have you checked all earth points, you will find them on Rave.