I have read through many different forum posts about similar problems but none of them seem to be exactly what I am experiencing or are for a pre 96 disco. I have a 96 disco 1 v8 NAS, and my dome lights stay on permanently and flicker. I have removed all the door switches to isolate whether it was the switches, but this didnt work and the problem persists. The other day I was playing around with one of the switches (the driver door) and for some reason everything began to work as normal. I closed all the doors, lights went out, tested a few more times and all good. I left the shop, and a few minutes later the lights came back on by themselves and stayed on (killed battery). I have not seen them work since. It is all 3 lights. Any ideas on how I can narrow this down would be appreciated (I read a great writeup which talked about using connector C277 for diagnostics, but I cant find this connector anywhere? It is not where the manual says it should be).

 

Make sure all door switches are well grounded via the mounting screw. They'll act all kinds of crazy if the surface isn't clean between the switch, screw and body.

 

Yeah so this was the first thing I went through, made sure each one was grounded well and it still didnt seem to make it work, but I will try again and see if it cooperates.

 

I did forget to mention that the lights stay on even though all of the door switches are currently removed from the car (and therefore not grounded, which would turn them on) and they are still all on

 

Could be one of the door switch wires has a short to ground. It only takes one. If a wire insulation rubbed through to ground, that might explain the flicker. I had a wire come loose at the driver door switch, if that wire had touched the door, it could have turned on the lights.

 

In your opinion, would this also cause the ignition light to stay on? The ignition light has always stayed on permanently, but the dome lights used to work fine. I think you are right in that it may be a wire grounding, because when I wiggle certain harnesses at the dash the lights flicker more.

 

That could be. My dome lights fade away gradually after closing the door a minute or so later. The key light turns off with the dome lights. The fade away feature must be some type of transistor control box.

I have not gone through the wiring diagrams for dome lighting. How hard could it be???

 

I see a lot of people are watching this thread so I will share my solution. I think a mouse ate through one of the ground wires behind the dash, which is why it was flickering. Heres how I solved it: I ended up intercepting the switched ground wire coming from the dome light down the A pillar. I cut it and ran a new wire to the driver door switch. Rear dome light and trunk light piggyback off the front, so all dome lights turn on when I open the driver door, turn off when I close it. This completely bypasses the MFU and is a very simple system. I then bridged the ground over to the passenger door switch as well, which allows them to also turn on from passenger door. If you were so inclined, you could bridge all of the doors so that it works like factory other than that they dont stay on for a minute and fade out. For me, this is a perfect solution and hope this helps others having issues with theirs.