Disco 2 Electrical issue...looking for help please! :)

Hi all,
Have a small electrical issue developed and electrics are not an area I know a huge amount about so figured I’d get some advice first before I start messing with things.
In the last couple of days, every time I press the brake pedal the left indicator (front, rear and side repeater) comes on as well as the brake lights. All the brake lights are on fine and the indicator flashes as normal when you put it on.
This might be a simple fix but as I said, I don’t know much about electrics so any ideas on where to start? Or what the possible cause could be?
Any advice appreciated
Thanks!

I assume the indication is static when the brake light is on? What u say is one symptom of a faulty earth connection, which has be known to be associated with the rear lamp units earth connection or bulb holders.

But unfortunately maybe not I your case, but it's something to check out.

discool said:

I assume the indication is static when the brake light is on? What u say is one symptom of a faulty earth connection, which has be known to be associated with the rear lamp units earth connection or bulb holders.

But unfortunately maybe not I your case, but it's something to check out.

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Yes that’s what I meant, it doesn’t flash, just lights up as if they are extra brake lights.
Thanks very much for your suggestion, I’ll have a look and see what I can see!

I'd agree sounds like an earth problem to me.

mcreedy18 said:

Yes that’s what I meant, it doesn’t flash, just lights up as if they are extra brake lights.
Thanks very much for your suggestion, I’ll have a look and see what I can see!

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Looksee that's about it, let the Forum know if u have a result or not.

As above , - Faults of this nature - "weirdness" across multiple circuits are nearly always earth related - as in, there is no "proper" earth, so the current return path for the brake lights (etc) has to find a route through another circuit .... which is what you are seeing here. ( sometimes seen on cheapo light boards for trailers too - where all the lights on one side flash as an indicator )

It's always worth checking earth straps on a pretty regular basis, and cleaning them up and then greasing them up with Vaseline to protect them.

D1's have been known to loose both LR earth straps, and then use the handbrake cable as a very poor substitute - this can soften the cable, leading to its failure, the handbrake getting released .... and you can guess where that ends up .

I once had a Mini whose engine earth strap failed so it earthed through the throttle cable (a fancy ptfe lined one). This made the lining melt & stick the throttle full open. Quite scary........

iansoady said:

I once had a Mini whose engine earth strap failed so it earthed through the throttle cable (a fancy ptfe lined one). This made the lining melt & stick the throttle full open. Quite scary........

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This happened to me when giving my then girlfriend a driving lesson in a metro. Just approaching a roundabout and i said start slowing down. She said i have taken my foot off but we are still doing 40mph.
It had earthed through the throttle cable and melted.
The stains eventually came out of the seats.

Ok, so I had a look at the rear lights, took them all apart on both sides, cleaned everything up, left hand side was quite corroded, cleaned it up, put everything back together and still the same problem checked the connections to the rear lights too and all seem to be ok, no obvious damage to wires etc.
I had a play about with the multimeter, the bulb holder itself seems to be ok, all connections there had no resistance. when i checked the connector to the bulb holder (with the brake pedal pressed), i got one showing about 12v, which i assume is fine, however the other three all read nothing, and also gave a reading of 1 when i checked for resistance. assuming iv tested them correctly that is, haha! i get so confused with electrics for some reason.
Where should I be looking next?!
Sorry if these are daft questions, I just have no clue when it comes to electrics, I think I overthink it and make it more complicated than it is
Thanks again!

Voltage at bulb holder should have been found at the pins inside only, the bulb holder itself is the ground or earth but only if required depending on the bulb type.

Earth both back bulb holders separately, get another bit of wire and a self tapper into the body, you can't have enough earths

Rodeo Joe said:

Earth both back bulb holders separately, get another bit of wire and a self tapper into the body, you can't have enough earths

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I agree that you can't have too many earth points, and though the self tapper is a bit barbaric for me, , OP, you could run a temporary earth return back to the battery for testing purposes .... if this makes the problem go away, then install something more permanent, and perhaps install same in a "nice" way

Function over form

Rodeo Joe said:

Function over form

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Yep !!

Disco1BFG said:

I agree that you can't have too many earth points, and though the self tapper is a bit barbaric for me, , OP, you could run a temporary earth return back to the battery for testing purposes .... if this makes the problem go away, then install something more permanent, and perhaps install same in a "nice" way

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thanks for the suggestion, ill give it a go! excuse my daftness but is there anywhere specific i should connect it to at the bulb holder end? don't want to go frying anything by accident

I'd put a scotch lock onto the earth in the loom for the light cluster and earth it to the body for starters, dunno what colour the earth will be tho... probably black but easy enough to check with a multitester.

mcreedy18 said:

thanks for the suggestion, ill give it a go! excuse my daftness but is there anywhere specific i should connect it to at the bulb holder end? don't want to go frying anything by accident

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Agreed - the smoke in the wiring loom needs to stay where it is So, I'd go from the battery -ve, to the -ve side of the bulb giving issues - or the -ve side of the light assembly in general. Even the cheapest multimeter will tell you which side is the -ve, earth return side - I'm sure there are vids on the tube of you explaining how to use a basic multimeter, should you need them

The LZIR map might find you someone close by to come and drink your tea