Skip to main content

MadaboutKitcars

This is a read-only archive of the old Madabout Kitcars forum. New posts and replies are no longer possible, but every thread is still here to browse and read.

BMW Headlight Wiring

MartinClan 13 Mar 2009, 9:44am
Having fixed my small problem with the fusebox I was able to test my headlights this morning. Strangely the dipped beam stays on when you select main beam (main beam does come on so both are on) Looking at the wiring diagrams I have from Diakom the relays in the fuse box seems to be wired that way. But the Bentley manual shows it wired how I would expect with the dipped going off when main is selected.

So which is correct? (Perhaps both are - different for different markets perhaps. My donor was a LHD imported from Switzerland) More importantly is it going to be OK for the MOT and SVA like that? I can't see anything that rules against it but I would like to be sure....

Cheers

Robin
GreatOldOne 13 Mar 2009, 9:53am
Isn't that right?

On my Jag, the main beam is a completely seperate light, and the dips don't go out when you put them on...

Don't most Xenon lights dip by putting a shutter over part of the light, to deflect it? So essentially, the light is always on dipped or not?
Stuart 13 Mar 2009, 1:52pm
Robin
My headlights are wired so both dip and main beam are on when full beam is selected that is how the E30 BMW is wired.
Patrick 13 Mar 2009, 2:07pm
Yup that's normal on BMW as the have two separate light units. The dip stays when you put the high on :)
peterux 13 Mar 2009, 2:39pm
I have a vague memory of reading somewhere that headlight lamps with dual filaments (one for dip and one for main) shouldn't be wired on together as they can overheat?
You don't get this problem if you have dual headlight clusters like the BMW. (Also, I suspect on older cars they didn't have the dynamo/alternator big enough to cope with both lamps on.)
The SVC headlights have these dual filament lamps so I wired mine with a changeover relay from dipped to main beam. My driving lamps also come on with the main beams so I have lots of light on the road.
My headlight flasher is wired to make the main beams come on with the dippped beams still on. (its like Blackpool when I flash my lights :madgrin:)

The worst your going to get is slightly premature lamp failure but with the amount of night driving your likely to do, I wouldn't worry about it before your SVA as it'll be a lot of re-wiring to change it now. (Just make sure you have a spare lamp at the SVA should the worst happen!!)
MartinClan 13 Mar 2009, 6:48pm
Ok - thanks guys. I may do something about it post SVA. I have also put in the wiring for driving lamps although nothing to connect them to yet. That would mean on full beam there would be 50 + 55 + 55 watts per side - 320 in total. Hmm you certainly see me coming....

BTW what did you guys do for driving lights? The SVC ones are a bit pricey.

Robin