Headlamp connections

[Jack]

No Haynes to hand at the moment, so can't check myself...

Headlamps - H4's have 3 wires to them; earth, dipped and main, correct?

Does the feed to the dipped beam cut off when the main beam feed goes on? If so, is there any way to preserve that signal with the main beam on? I would like my dipped beam to stay on when I hit main beam on the stalk...

Could I just wire both the main and dipped beam (that goes into the H4 bulb connector) into the main beam lamp?

[meritlover]

yes it does cut-out.

i cant remember if this is a function of the stalk/switch. or the dim-dip relay. probably the latter.

[Jack]

If I chopped the H4 connector off, then connected the main and dipped beam wires together and joined them to the bulb, would that damage the relay?

[Spudly]

Possibly, iirc the flash feed uses both dipped and high beam but dont know if thats a stalk function though but could you not use the feed from there?

[Jack]

No, because I don't want to have to hold the stalk backwards to turn high beam on

[Welsh Dan]

You could use a normally open relay between the positive terminals for both bulbs, and use the main beam feed to switch it 'on' to 'closed', so that when main beam is switched on dipped beam is aswell, but dipped beam will also operate on its own. In conjunction with that though I'd run a live feed from the battery to main beam, and use a relay to switch that aswell.... or use a relay with 2 switched pairs to do the job in one.

If you just join the positive terminals they'll all be on or all be off....

[meritlover]

If I chopped the H4 connector off, then connected the main and dipped beam wires together and joined them to the bulb, would that damage the relay?

i wouldnt have thought so, however, your high beam circuit is now driving your highbeam and main beam lamps, and may be over-loading. i woud doubt damages would occur to the relay as that switched contact would be open circuit anyway so wouldnt really be back-feeding anything.

however, i hope that we are still friends

[Jack]

Mr Meritlover you are my bestest friend

You could use a normally open relay between the positive terminals for both bulbs, and use the main beam feed to switch it 'on' to 'closed', so that when main beam is switched on dipped beam is aswell, but dipped beam will also operate on its own. In conjunction with that though I'd run a live feed from the battery to main beam, and use a relay to switch that aswell.... or use a relay with 2 switched pairs to do the job in one.

If you just join the positive terminals they'll all be on or all be off....

I've read that 3 times and still need to read it again

At the moment I have a relay which takes a switching feed from the full beam wire on the H4 connector to drive the inner lamps (the old cibie lamps had H4 dipped/outer, H1 main/inner). So I think I see what you mean about all being on or all being off.

How about joining the dipped and main beam feeds, then putting a diode in after the relay feed to stop power going back up to the relay and keeping the main beam on?

Like this:

[Welsh Dan]

That would work provided you use a suitable diode.

[Jack]

Next question, what would be a suitable diode? The scope of my electrical skillz goes about as far as crimps and solder