Hi All,

I've got an electrical issue with my FD, it's actually failed the MOT here in the UK because of it.

Basically as the subject states, when my side lights are on, and I indicate/turn the hazard lights on, the side lights dim EVER so slightly in time with the indicators, but obviously enough to fail and MOT!

I've tried earthing the bulbs directly however my side lights are still dimming.

could the issue be with the flasher unit drawing to much current or something?

So far i've

- taken front bumper off and cleaned up earthing points
- cleaned up boot earth point
- cleaned up engine earthing points
- ran direct earth cables from the bulbs themselves to test

the thing I don't quite get is why the side and dash/vanity lights dim, as they are on a separate circuit to the hazard/turn lights presumably?

Any help would be much appreciated as I'm pulling my hair out now!!!
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See if it does the same when you turn your fan all the way up or when you step on your brake lights.. What kind of voltage is your alternator putting out? Also, how old is your battery?

 

It does the same when I step on the brake pedal, Alternator is putting out 14v according to the PFC, battery is new. It does it if the engine is running or not.

 

I have the same issue on both of my 7s

 

It sounds like high resistance in a ground but you mentioned you already grounded them individually. Maybe the high resistance is in the control? I'm going to check the wiring diagrams and see if I can help lead you to the problem.

 

Mine does the same think
It's a stockish 20k mile Jdm model

 

I've been reading alot about this, over the years it seems that this is an issue that plagues alot of FD3S owners.

I'm convinced that the White/red cable from the 60amp Btn fuse to the Joint box under the dash is too thin, it's the same thickness as the 40amp fuse cables?

 

My car does the same thing, and I'm here in the states. But it doesn't do it when I use and lights or turn on my hazards. It does it when I open the door or the hatch, and it doesn't hardly ever stop.

My side lights flash, dome light flashes, and I hear something ticking, like my blinker or hazards are on.

Very very annoying.

 

It doesn't sound exactly the same as my issue, similar but not the same,

Anyway I just had to wire my sidelights into their own 12v circuit to get it through the MOT today. When doing that I found some really interesting things happening. I unplugged ground points 11 and 12 and the hazard lights still worked (according to the electrical manual they shouldn't!). So when I get a good day I think I just need to remove all the boot trim etc and find out just what is going on with the wiring there!

One good thing though is I've learned how to read the electrical manual and i've got a good idea of how most of the systems work, and where everything should earth to!!

 

Alternator died today
Hopefully that was my only issue