LED Bulbs

MULLEY · Post by **MULLEY** » Sat Feb 18, 2012 6:21 pm

Wasn't sure if they would help with voltage drop or not, but was interested to know whether fitting higher output bulbs could melt anything & so these might help, i found some BX specific one's from the same place that were slightly cheaper. Worth buying or don't bother?

Oilyspanner · Post by **Oilyspanner** » Sat Feb 18, 2012 7:23 pm

The risk with brighter bulbs is too much current going through the switchgear, I was amazed by the increase in light I got from the standard bulbs when I fitted relays to the main/dip circuits, cheap too, the relays were under £3 each and a few feet of cable, do that first then upgrade the bulbs if you still need more light.

MULLEY · Post by **MULLEY** » Mon Feb 20, 2012 9:59 pm

Relay's & cable, sorry, no idea what you mean

For a simpleton like myself when it comes to electrics, a picture is a thousand words if you know what i mean

Don't suppose you've got a picture of what a handmade one looks like, & how its all connected upto the battery?

Mickey taker · Post by **Mickey taker** » Mon Feb 20, 2012 10:32 pm

[quote="Oilyspanner"] I was amazed by the increase in light I got from the standard bulbs when I fitted relays to the main/dip circuits, cheap too, the relays were under £3 each and a few feet of cable, quote]

common upgrade on MK 2 golfs ,
basically the wiring go's all over the place between the battery , switch and bulb, so if you put a relay in the circuit so that it switches when you put the lights on , the juice go's more directly to the lights so less power is drained .

relay needs an earth and fused (30 amp) cable from battery then the feed from the switch to the lights is interupted,
go's to the relay to "switch" it on then heavier weight cable is used from the other side of the relay to the lights.
(old feed to the lights is discarde after the relay)

Mickey taker · Post by **Mickey taker** » Mon Feb 20, 2012 10:34 pm

here you go

http://www.matey-matey.com/uprated_head ... ring.shtml

Mickey taker · Post by **Mickey taker** » Mon Feb 20, 2012 10:34 pm

http://www.matey-matey.com/tech_diag.shtml

BX Meteor · Post by **BX Meteor** » Mon Feb 20, 2012 10:44 pm

what he means is, the "on/off" switch for headlights in a BX is normally at the end of the headlamp stalk i.e. the lighting stalk that you move to select lights, is a switch, and that switch carries the current from the battery, through the switch, to the headlights.

Those switches are designed to carry a certain current, and if you exceed the rated current then the switch will overheat, possibly melting the plastic around the contacts, and/or possibly melting the contacts.

The way to control higher currents is to use a relay that can carry the higher current. The easiest solution in this case (from a wiring point of view) is to buy 2 relays from somewhere that can carry the rated higher current. You then fix each relay close to the headlamp.

A relay has 4 connections, 2 to/from the relay coil, and 2 to/from the relay contacts (the relay contacts are electro-magnetically controlled by the relay coil).

For each headlamp, you take the wire that feeds power to the headlamp, and re-route it to the relay coil (you have to earth the other connection for the relay coil). Now the headlamp stalk will switch the relay (which you would hear clicking if someone turns the stalk in the car).

You then bring a fat feed wire from the battery (put an inline fuse at the bettery end) to one of the relay contacts on the relay, and then a wire from the other relay contact to the headlamp.

The stalk in the car now switches the relay on/off, then the relay switches the headlamp on/off.

You need 2 relays, brackets, fat wire, inline fuse(s), cable ties, crimps, connectors, and good grasp between finger and thumb.

Post by **mat_fenwick** » Mon Feb 20, 2012 11:51 pm

I've fitted relays to mine, but not noticed much of a difference - I think I'd have to put them back to back to tell. This is with 55/100w bulbs too (which common wisdom has it will melt your headlamp switch) which I'd expect to highlight any issues with the original wiring. I can only assume that my original wiring was already in good condition, and not suffering much voltage drop.

Oilyspanner · Post by **Oilyspanner** » Tue Feb 21, 2012 12:12 am

My Mk1 had an electrically heated dashboard

Post by **Defender110** » Tue Feb 21, 2012 1:11 pm

I didn'realise BX's were a direct feed without relays, I thought all headlamps were relay fed.

BX Meteor · Post by **BX Meteor** » Tue Feb 21, 2012 2:48 pm

I had to check on the circuit diagrams in Haynes just to be 100% sure. The fog lamps have a relay, but not the headlamps.

Headlamps are 488/489 in the circuit, each lamp (main and dip) is shown as a circle with a cross, with two feeds, one for main, one for dip. No relay for headlamps (260 is the switch block on the end of the stalk)

Fog lamps are 447/448 in the circuit. Fog lamp relay is 750.

I've put red boxes round them, but the red is not very bold.