22 replies to this topic

[Hegnirst]

If i put a bigger wattage bulb, e.g. a 90 or 120 watt bulb in, in place of the 55 watt bulb would i need to change my wires? would the wiring melt or something because of more current? I am fully aware about the 'e marked' etc the way i see it, xenon lamps now a days are ridiculous and are in some ways dangerous

thanks for the help!

[miniyellowmini]

Yeah you will fry the standard wiring with higher wattage bulbs. Over a certain wattage they are also not road legal

Edited by miniyellowmini, 21 February 2013 - 11:01 PM.

[mini13]

also the std switches will die, or at least the ones in the stalk.

the best way to achive what you want is to mount relays on the inner wing and use the existing wiring to activate them, then run fresh wiring to the head lamps.

[OfMini&Men]

55/60 watt is all mot will allow.

[Cooperman]

To run 100/80 headlight bulbs you need to re-wire and run 4 relays - one for each of the two main beams and one for each of the dipped beams.
Legality is not really an issue as it woulkd be so difficult to check as the headlights need to be stripped out to get at the bulbs.
I run 100/80 headlight bulbs and have nefver had a problem. I think they look less bright than some modern Xenon Gas Discharge lights.

[MRA]

The above is what you should do....

However if you increase the size of the black wires to ground then you can get away with it, I have for over 12 years....

Do not fit a diode to make all 4 come on when on high beam as this will melt a few parts...

But 240 watts is 20 Amps, which equates to about 2mm CSA of wire, most especially later Minis from early 80's at least have already got 2mm wiring.

Use 3mm or larger for the ground wires, the larger wire will pull heat away from the connector, it is the connector that fails first causing the rest of the system to follow suit...

Do NOT hold the flasher switch in the on (flash) position, either turn it to main or dip, or flash and let go, as these tend not to like high current.

I run 130/90 in all my Minis and my Discovery and have done so for years, as I say the correct method is outlined above, in other posts but you can use the existing circuits if the system is in good health..

PS. I think you mean HID lamps.... imagine these when the "I can't be arsed to fix my car" brigade get hold of the latest systems......

Edited by mra-minis.co.uk, 22 February 2013 - 01:25 AM.

[Hegnirst]

To run 100/80 headlight bulbs you need to re-wire and run 4 relays - one for each of the two main beams and one for each of the dipped beams.
Legality is not really an issue as it woulkd be so difficult to check as the headlights need to be stripped out to get at the bulbs.
I run 100/80 headlight bulbs and have nefver had a problem. I think they look less bright than some modern Xenon Gas Discharge lights.

exactly my point :) there wayyy brighter!!
4 relays?? so which wires are they then? and how far away from the bulb? thanks for the help!

[Hegnirst]

The above is what you should do....

However if you increase the size of the black wires to ground then you can get away with it, I have for over 12 years....

Do not fit a diode to make all 4 come on when on high beam as this will melt a few parts...

But 240 watts is 20 Amps, which equates to about 2mm CSA of wire, most especially later Minis from early 80's at least have already got 2mm wiring.

Use 3mm or larger for the ground wires, the larger wire will pull heat away from the connector, it is the connector that fails first causing the rest of the system to follow suit...

Do NOT hold the flasher switch in the on (flash) position, either turn it to main or dip, or flash and let go, as these tend not to like high current.

I run 130/90 in all my Minis and my Discovery and have done so for years, as I say the correct method is outlined above, in other posts but you can use the existing circuits if the system is in good health..

PS. I think you mean HID lamps.... imagine these when the "I can't be arsed to fix my car" brigade get hold of the latest systems......

so i could technically just add very thick black wire? instead of the relays? so the thicker the wires, the less need for relays? and the less chance for wires burning out?

[Hegnirst]

55/60 watt is all mot will allow.

then wouldnt know, plus i have yellow tints so i doubt it would really matter to be honest! think of HID's? there ridiculous!

[Hegnirst]

also the std switches will die, or at least the ones in the stalk.

the best way to achive what you want is to mount relays on the inner wing and use the existing wiring to activate them, then run fresh wiring to the head lamps.

the old switches would die?
so old wire too a relay then from the relay too thick wire too the head lamps?

[Hegnirst]

Yeah you will fry the standard wiring with higher wattage bulbs. Over a certain wattage they are also not road legal

ooo lovely :) yea i know there illegal :)

[Willthewelder]

No, You only need 2 relays, as most standard relays are rated to 30a constant load at 12vdc,
They only draw about 20ma to throw the pole and make contact so the stalk switch is more than capable of it.

A 55W bulb will draw 4.5a at 13.5V so the 100w bulbs will still draw less than 10A x2.

Run a fused feed directly from the solenoid permanent pos and make the switched side on the pos and a permanent earth.

[Cooperman]

Can't really see the point of brighter bulbs if the output is going to be reduced by yellow tinting of the lens.
The reason for one relay per bulb filament is to prevent total loss of either main beam or dipped beam should (or when) one relay fails. That makes the headlights 'fail-safe' (as in aircraft engineering) and that is a dood thing and at the cost of 2 extra relays not expensive or complicated. That way each bulb filament can have its own separate fuse as well.

[Willthewelder]

A relay is no more likely to fail than the switch. Providing you use good quality relays (I only use bosch) you should never have a problem

[tiger99]

Yes, you MUST use 4 relays, or you are introducing significant extra failure modes which can cause the sudden loss of headlights, and a probable accident, if it happens on a dark night. Single relays are not used in headlight circuits, but some more recent vehicles have used double coil, double contact relays, which used a single earth on the fixing bolt and also proved to be unsafe, and are probably not now legal. It is in any case far cheaper to use 4 standard relays than anything special.

Make sure that you split the earth returns when altering the headlight circuit, as a very common failure on Minis involves the single earth return, which again is not legal on new cars. The left and right lights should each go to a seperate earth, and same at the back.