Strange Brake/Lighting Problem

A friend was driving behind me and told my left brake light was out.

I got two new bulbs, changed over the brake light one.

Brake light now works.. but when I put my foot on the brake my headlights flash!

With the lights on, the brake lights don't work, but are stuck on.

Any remote idea what could be happening??

I had the same thing happen to a Corsa I once had. Turned out I used the wrong bulbs.

Right lets hope its a bulb then, still not investigated

Mine as just started doin the same did u get it sorted if so was it just a bulb

Tarantula said:

A friend was driving behind me and told my left brake light was out.

I got two new bulbs, changed over the brake light one.

Brake light now works.. but when I put my foot on the brake my headlights flash!

With the lights on, the brake lights don't work, but are stuck on.

Any remote idea what could be happening??

Click to expand...

Check youve put the correct bulbs in! Guess you've put single filament bulbs in twin filament holders so the brakes will put on the side lights cos it shorts to that circuit in the holder! And vice versa when side lights on it shorts to brake and puts that on!

Basically they should be stop/tail bulbs you've used stop only ones!!!!

At a guess

Nah still haven't sorted, been preoccupied with another car's problems

Oh good!!!! I hoped I was just being thick. I was sure I picked up the right ones.

Right awkward fcker to access too, the bulbs.

Went to Halfords, checked their log thing and bought 2 x #382 single filament bulbs - which it says is right for brake light, and also right for tail light.

Yesterday I had no left brake light, and no left light.

Changed the top (light) bulb. Then had no brake lights on either side.

Changed the bottom (brake) bulb. No effect.

Any idea? This is driving me bloody mad

Especially as I've got a 20 mile journey home full of traffic, with potentially only the top centre brake light.

Tarantula said:

Went to Halfords, checked their log thing and bought 2 x #382 single filament bulbs - which it says is right for brake light, and also right for tail light.

Yesterday I had no left brake light, and no left light.

Changed the top (light) bulb. Then had no brake lights on either side.

Changed the bottom (brake) bulb. No effect.

Any idea? This is driving me bloody mad

Click to expand...

Lets start on the model year of your disco as some are single filament and some are twin.
As twin filament bulbs have stagged locating pins it would be very difficult to install it single ones that don't have staggered pins.

The method of retaining and connection to the bulb in the lamp unit on a D1 is a very iffy light weight item and limited space so also check that the holder is undamaged and fitted correctly.

Sorry, 1997.

I did check in halfords and on a bulb website a minute ago, both said for my year 382 bulb is the right one.

The bulb holders have got 3 like sticky out bits in a triangle, which slot into the light.

It might well be knackered holders then I guess, I did have a right p!ss about trying to get them in/out, the many, many times I've done it.

Standard holder then which are keyed (three cutouts/locating pins which one is wider) line up and twist, 1997 would have a twin filament bulb.. combined rear and stop and then single for indicator, reverse and the rear fog..

Look in the holder where the bulb goes, how many contacts? 2 or 1? If its two it's a twin filament, if it's one it's a single filament! Even tho they're designed with offset pins etc I've seen it loads of times where people wedge the wrong bulb in! It's easy to do! don't believe the books. If you put a single filament bulb in a twin filament holder you short the sidelight and brake circuits together giving very odd lighting results, that's why it was the first thing I said to check, it's a common mistake!

Right yes that's very helpful actually, the two contacts! I just found a twin filament bulb, put it in the top light slot (left light cluster), and suddenly that light worked as both light and brake light.

However, I now have no brake light on the right! I guess the bottom light also needs twin filament. Will have to pick some up and try again.

FFS Halfords.

Thank you all so much!

Tarantula said:

Right yes that's very helpful actually, the two contacts! I just found a twin filament bulb, put it in the top light slot (left light cluster), and suddenly that light worked as both light and brake light.

However, I now have no brake light on the right! I guess the bottom light also needs twin filament. Will have to pick some up and try again.

FFS Halfords.

Thank you all so much!

Click to expand...

Bottom light? if that means the one in the bumper then they are single fillament 5w. Don't u have an owners handbook? all the info u need is in there.

No, I mean the bottom light of the cluster.

Bumper lights working fine.

One headlight's stopped working now :

Tarantula said:

No, I mean the bottom light of the cluster.

Bumper lights working fine.

One headlight's stopped working now :

Click to expand...

Bottom light is the 'fog' so that a 21w bulb.

Lol whoops.

As you can see this has made me lose my sanity somewhat

Would have been fine if I could have got to the f#cking bulbs easier!

Tarantula said:

Lol whoops.

As you can see this has made me lose my sanity somewhat

Would have been fine if I could have got to the f#cking bulbs easier!

Click to expand...

I have noticed that u have not complained about access to the bulbs, so I take it u don't have seats in the boot.

The only bulb I've only replaced at the rear is the o/s stop-tail... twice, it's a pain as you have to use the left hand (i'm R'H) to fit the bulb and only after loosening the seat bolts or working through the half open seat brackets.

Haha yeah, at above, best to remove the top two side seat bracket bolts or just take the ****erout if you dont use it. Have similar prob after taking out the offside rear light cluster to sort out corrosion on the body. Voltage to cluster but no light or brake light at the same bulb , bulb is ok ..so am going to remove the whole light to check the metal strip wiring to holder... and solder to repair if necessary.
And the headlights are doing strange things..but the earths seem ok ..