When I'm idling and I put my foot on my brake my dash, head and rear brake lights dim/flicker dimmer.


It's strange, when I press the brake just enough for rear lights to come on the headlights dash and brake lights flicker/dim really quickly for about 2-3 seconds like it's surging/draining power from somewhere.

And if I press the brake, let it flicker, then let go and quickly press brake peddle again it doesn't do it, it's like it has to build up some sort of charge?

My rev counter needle also jumps up quickly then back to its position often, even with just key in to position II a and not started.


Any ideas please?

Thanks

 

The lights problem sounds like poor earth connection/corroded rear light connections. Remove the rear lights and check the connections and bulb holders, and the wiring going to the holders. Also make sure correct bulbs are fitted, if a single contact bulb is in place of a double contact it can cause issues.

Have not come across the rev counter fault, possibly be a new instrument cluster required..

 

Found out tonight that it also happens when the car is coming down to idle from any revs.

 

As GVK. said a bad earth had the same probs rear lights connections common fought.

 

Where are the earth points for the rear lights? Are they easy to find?
Thank you

 

The problem is normally down to the connector blocks that plug onto the bulb holders give the prongs on the bulb holders a good clean with some emery paper and check the contacts on the plugs are also clean this normally sorts the problem out.

 

Brilliant I'll remove the units tomorrow and check them thank you.

 

I've checked the rear light connectors, earth straps in engine bay, the battery one, front drivers side from healights and rear head one. But it's still doing it.

 

Theres another earth in the drivers footwell, check that one as well, Cant remeber if there are any others

 

Thanks, Do you know where abouts in the footwell?

It's strange, when I press the brake just enough for rear lights to come on the headlights dash and brake lights flicker/dim really quickly for about 2-3 seconds like it's surging/draining power from somewhere.

And if I press the brake, let it flicker, then let go and quickly press brake peddle again it doesn't do it, it's like it has to build up some sort of charge?

 

Hope you get it sorted

 

sorry mate ignore me just realised you have a focus

 

would go for a separate 2,5 mm˛ cable on both lamp carriers to body shell.

 

Been reading a lot about this on American forums and found few things to check:
- I'll check the battery terminals for corrosion under the grease.
- seen something called 'The Big 3' which is replacing all the cables from alternator to battery with new larger gauge wire.
- check the pig tail on the alternator for corrosion.
- the wires in the harness from car to tailgate, I did check these but dot know how I would get to them to check all the way along?
I'll start with the pigtail and Battery terminals on Thursday in my day off.

 

clocks are wired into the rear lights and by the sound of it theres a crossed wire or two expossed wires touching each over. due the reasons of stealing cars i cant say which wires over ride the ingtion but its very unlike to be on the tail lights end. pull the front an rears seats out and follow the loom from the boot all the way around to the fuse box you will find broken or pinched wires along there.
Thats the cause of your problems.
to help follow the light looms from the bumper not the tail lights there the cause.

 

Would this also be correct as the lights flicker when the revs drop without foot on brake?

 

Random question, is the stereo aerial connected to the lights at all?
I'm loosing radio signal where I've always had it before and I can't pick up any radio station at all and then randomly it'll come back.

 

So I checked all cables on battery and alternator and they 'look' ok but few of the copper earth cables from battery to inner wing look a bit green at the fixing point in the wing.

I was having a play this morning and at idle if I turn side or headlight on, fog lights on, rear heated window all on their own the lights would dim/flickers as well.
Could that be something to do with the alternator or earthing from the battery?