MadaboutKitcars

As I remember the E30 had two bulbs in each double headlight. A combined Main/Dip in the outer one and a Main only in the inner one. Which means, when on full beam you have all four headlights operating on full beam. Is that correct?

The reason I ask is that I have replicated this on my Sportster with the two lower spotlights wired as the "inner main beam". The problem is that, when on main beam, it blows the standard fuses which are only 7.5 amps each side. So what was the wattage of the original headlights? 7.5 x 12 only gives you 90w in total. I would have thought two main beam lights was more than this. They are normally rated at 55w each.

I sloved the problem temporarily by fitting 10A fuses - but I would like to know how BMW got away with just 7.5A fuses in the first place....

Robin

You sure they are not like the newer BMWs with side light/high beam in the middle and dip on the outside?

I've got my spots wired in with the high beams, but I don't recal the fuse value.

That would certainly explain it. But I was sure, for some reason, that was not the case. Perhaps my memory is playing tricks hwell:

Cheers

Robin

That's how I did mine as well - on with high beam, if they're selected via switch on the centre console.

My fuse ratings are:

Dips - 25A
Driving - 25A
Mains - 30A

From the donor handbook (and my admittedly poor memory) all 4 bulbs were H1 and dip is outers only on. Main all four on. You are correct in that the fuses are 7.5A but there is one for each bulb. High beam inners go through relay K3 and dip outers through relay K4.

Thanks Sorton.... That confirms it then and explains the 7.5 amp fuses. It means I will be pulling a bit more through the headlight relays than they were designed for. But - it is old school BMW - so I guess that they are well overrated.

Robin