12 replies to this topic

[ImagoX]

I'm replacing my dim, stock headlamp units (stock wiring with voltage sent through the headlamp switch in the cabin) with modern replacements - the one I plan to use will use 100 Watt Hyper-white H4 Xenon bulbs. Since this is a major increase in current, I know that I will need to replace the stock wiring setup with one that uses relays to actuate the main and high beams to keep the cabin switch from melting. I've also heard that an ideal setup uses a PAIR of relays, one for the low beams and one for the high beams.

What I'm not sure about is where to tap in for the triggering voltage. Do people usually run leads from the steering column-mounted headlamp wand for the triggering voltage, or do you tap in elsewhere? I remember seeing a How-to with photos either here or over on the other UK Mini forum, but I'm not able to find it again.

Also, assuming that I'll be sending 200 max Watts through those headlamps, would I use a 20A fuse on the lead hooked to the starter solenoid (or a different, better positive lead), assuming:

100 watts divided by 12V = 16.66A + overhead

Obviously, if someone has a better idea than to run a direct line to the solenoid with a fuse in-line to power the newly-wired headlights, I'd love to know about them.

NOTE: In case it's relevant to this discussion, I currently have my 4 rally lights wired via relay to the starter solenoid (independently fused and switched) using one of the switched fuses on the main fuse panel as a triggering source for the relay. This way, if I turn on the cabin switch for the rally lights, they will illuminate ONLY if the ignition key switched on - saves me the possibility of leaving them on by accident. I'd like to wire the headlights up so that they can be switched on with or without the key, just as they work with the stock setup.

Thanks!

Edited by ImagoX, 11 February 2008 - 06:38 PM.

[langers2k]

100W headlights will be illegal for road use.

The easiest way to upgrade the wiring is to cut the connection between the switches and the headlights and add a relay in there. If you want to you can also replace all the wiring between the headlights and the relays. I think that would be the easiest way, and it would keep the same functionality as you have now, as long as you feed the relays from the starter solenoid...

[ImagoX]

100W headlights will be illegal for road use.

The easiest way to upgrade the wiring is to cut the connection between the switches and the headlights and add a relay in there. If you want to you can also replace all the wiring between the headlights and the relays. I think that would be the easiest way, and it would keep the same functionality as you have now, as long as you feed the relays from the starter solenoid...

Yes, I plan to replace all the stock wiring, just to be sure I understand where all the connections are. What I'm unsure of is the relationship between the cabin switch above the heater to the steering column switch that controls the high/low beams. I'm assuming I'll need to trigger the high-beam relay from the column switch, but I'm not sure what wires those are, or if I'll also need to trigger the low-beam relay from that same place.

PS - I am in the USA - 100W lights are perfectly fine here - they don't even inspect my car since it's a "classic" older than 25 years.

Edited by ImagoX, 11 February 2008 - 06:46 PM.

[langers2k]

Not completely sure what the relationship between them is, but if you take the feed as it goes towards the headlight then it doesn't matter.

So instead of trying to figure out the switch wiring, follow the loom from the back of the headlight and add the two relays to that. Does that make sense? So you would have a normal headlight loom, but instead of going to the headlight, it would be used to switch the two relays which would then be wired in to the headlights.

[ImagoX]

Not completely sure what the relationship between them is, but if you take the feed as it goes towards the headlight then it doesn't matter.

So instead of trying to figure out the switch wiring, follow the loom from the back of the headlight and add the two relays to that. Does that make sense? So you would have a normal headlight loom, but instead of going to the headlight, it would be used to switch the two relays which would then be wired in to the headlights.

I think I get what you mean. So leave intact all the wiring leading to the switch panel yheadlamp switch and the high-beam wand switch, but interrupt that circuit on the engine-side of the firewall, and connect it up so that all the stock circuit does is provide a trigger voltage to a pair of relays. The actual headlamp power comes from the starter solenoid, driven by said relays. This way, 100% of the TRIGGER VOLTAGE ONLY goes across the cabin switch (petty minimal) and 100% of the lamp voltage (16.66A) goes from the solenoid, across the relay, to the lamps.

Can anyone ID the wiring colors for the main beam, high beam and parking lamp so I splice them correctly?

If it sounds like I have something conceptually wrong, please advise... Thanks!

[yorkshirechris]

White with a Blue tracer is the High Beam (which we call Full Beam)...

[langers2k]

I think I get what you mean. So leave intact all the wiring leading to the switch panel yheadlamp switch and the high-beam wand switch, but interrupt that circuit on the engine-side of the firewall, and connect it up so that all the stock circuit does is provide a trigger voltage to a pair of relays. The actual headlamp power comes from the starter solenoid, driven by said relays. This way, 100% of the TRIGGER VOLTAGE ONLY goes across the cabin switch (petty minimal) and 100% of the lamp voltage (16.66A) goes from the solenoid, across the relay, to the lamps.

Can anyone ID the wiring colors for the main beam, high beam and parking lamp so I splice them correctly?

If it sounds like I have something conceptually wrong, please advise... Thanks!

That is how I would do it, easy to fit, and easy to revease if you ever needed to...

Not sure about the colours etc, to get them I would unplug one of the existing head lights and use a multimeter to figure it out

[ImagoX]

I think I get what you mean. So leave intact all the wiring leading to the switch panel yheadlamp switch and the high-beam wand switch, but interrupt that circuit on the engine-side of the firewall, and connect it up so that all the stock circuit does is provide a trigger voltage to a pair of relays. The actual headlamp power comes from the starter solenoid, driven by said relays. This way, 100% of the TRIGGER VOLTAGE ONLY goes across the cabin switch (petty minimal) and 100% of the lamp voltage (16.66A) goes from the solenoid, across the relay, to the lamps.

Can anyone ID the wiring colors for the main beam, high beam and parking lamp so I splice them correctly?

If it sounds like I have something conceptually wrong, please advise... Thanks!

That is how I would do it, easy to fit, and easy to revease if you ever needed to...

Not sure about the colours etc, to get them I would unplug one of the existing head lights and use a multimeter to figure it out

That would work... Typical me, trying to overwork the solution.

[langers2k]

That would work... Typical me, trying to overwork the solution.

Good luck! Can you do the wiring mods before you change the bulbs and then report back and tell us if there is difference?

If there is I may do it myself

[ImagoX]

That would work... Typical me, trying to overwork the solution.

Good luck! Can you do the wiring mods before you change the bulbs and then report back and tell us if there is difference?

If there is I may do it myself

Difference how? Are you thinking that the stock wiring setup is absorbing some of the current and dimming the stock bulbs? Seeing as how my replacements plug into the exact same harness, I can easily plug in the stock lamps to my redone wiring, sure - it's what I planned to do before yanking everything out as a matter of fact, since I KNOW the lamps that are in there now are in good working order (just... dim).

I have nothing to measure the output except for my own two (admittedly aging) eyes, though, so my results will be anecdotal only.

[Jammy]

If your able to wait about a week I'll be doing a product review on the Halogen upgrades available, compared to the standard sealed beams, and it should include a bit about fitting the relays.

[langers2k]

Difference how? Are you thinking that the stock wiring setup is absorbing some of the current and dimming the stock bulbs? Seeing as how my replacements plug into the exact same harness, I can easily plug in the stock lamps to my redone wiring, sure - it's what I planned to do before yanking everything out as a matter of fact, since I KNOW the lamps that are in there now are in good working order (just... dim).

I have nothing to measure the output except for my own two (admittedly aging) eyes, though, so my results will be anecdotal only.

Pretty much, I know the standard switch can get warm because of the current flowing through it so I was curious to see if it absorbs much power.

You could measure the voltage across them as well? But anything you notice would be good!

If your able to wait about a week I'll be doing a product review on the Halogen upgrades available, compared to the standard sealed beams, and it should include a bit about fitting the relays.

That would be cool, will you be covering if relays make any difference and not just how to fit them?

[ImagoX]

If your able to wait about a week I'll be doing a product review on the Halogen upgrades available, compared to the standard sealed beams, and it should include a bit about fitting the relays.

Surely... It's about -5 degrees Fahrenheit in my garage this week (-20c to you guys), so I'm in no tearing rush to get them installed - I was just moving to get my ducks in a row so that when I DO get a warm day I can pounce.

FYI - the ones I went with were these, with the H4 xenon hyper-white bulbs, in case you need assistance with these for your review:

http://www.gbcarpart...d=Lamp7Headlamp