I was looking in the Headlight FAQ and i was wondering if people can answer the questions referring to the 2nd Diagram (upgraded wiring) in this link

http://www.danielsternlighting.com/tech/relays/relays.html

What colour is the wire that goes from the switch to the headlight connector (on my Parras in my Magna) to power them? (its the ones that need to be run to the relays)

Also i will probally take the easy route and connect the relays to the battery instead of the alt, no issues here right ?

Also what amp fuses should i use between the battery and the relays ?

So why do you want upgrade the lights for why not add a set off spotlight to the front of your car? Secondly your car already has a relay for the headlights. Plus with magna they have a set of driver light built in. When you flip high beam you have a set of high beam light plus another bulb. So I reckon the magna can't be beaten for light output :) in highbeam.

I'm probably totally wrong here, but aren't Magna headlights 'hot' all the time like Toyota's - with +12Vdc at the bulbs all the time.....the illustrations in the link apply to the earlier wiring style common to 'ordinary' cars.
Like I say - I could be totally wrong.

in my mind you only really need to use relays when your upgrading your bulbs from 55w to 100w. so if your upgrading your bulbs to 100w bulbs your best running relays to take the stress away from the headlight switch or youll run the risk of burning it out. is the right?

Look at my figures at the end of the Headlamp FAQ's.

The wiring on the Magna Gen 3 is very thin, I measured the voltage at the headlamp connectors on a Sports with Parabolics on Main Beam. Couldn't easily get to the back of the dip beam connectors.
Heath Young, who I understood worked for a major headlamp manufacturer in Australia, several years ago recommended relays and thicker wiring as a must have for improved output.
The fix isn't actually the relays, it is actually the thicker wiring with significantly lower voltage drop.

DO NOT take any unfused wring across the front of the car in front of the engine.
The correct thing to do is to run a HD fuse straight off the battery, Split the circuit, short side going straight to the relays for the LH headlamp. The other branch is the tricky one as it has to go back to the engine bulkhead, across it and then back to the area behind the RH headlamps.

Here is what I posted earlier :-
Voltage drop is 1.45V.

Test 1.
Engine OFF.
Voltage at battery under load = 12.03 V
Voltage at LH High Beam bulb holder = 10.57 V
Difference = 1.46 V

Test 2.
Engine IDLING.
Voltage at battery under load = 14.07 V
Voltage at LH High Beam bulb holder = 12.61 V
Difference = 1.46 V

Had a look at the wiring to remind myself just how thin it is!!
Looks like a trip to get 4 relays, 4 bulb connectors and some nice thick wire!

Here is the table from the Daniel Stern site.

10.5V : 510 lumens
11.0V : 597 lumens
11.5V : 695 lumens
12.0V : 803 lumens
12.5V : 923 lumens
12.8V : 1000 lumens ←Rated output voltage
13.0V : 1054 lumens
13.5V : 1198 lumens
14.0V : 1356 lumens ←Rated life voltage
14.5V : 1528 lumens


The Europeans take a slightly more realistic with their voltage ratings; they consider output at 13.2v to be "100%".
The loss curve is the same, though.
When operating voltage drops to 95 percent (12.54v), headlamp bulbs produce only 83 percent of their rated light output.
When voltage drops to 90 percent (11.88v), bulb output is only 67 percent of what it should be.
And when voltage drops to 85 percent (11.22v), bulb output is a paltry 53 percent of normal!
It is much more common than you might think for factory headlamp wiring/switch setups to produce this kind of voltage drop, especially once they're no longer brand new and the connections have accumulated some corrosion and dirt.

See the effect of the voltage drop when the engine is running from 14.07 to 12.61 Volts. This reduces the potential light output from 1356 lumens to 803 lumens, a 553 lumens or 40% drop.

When I did the 4 headlamp Capri in the 80's I rewired with what was normally used as the main feed cable in a van wiring loom, this was probably 4 mm2, as I was working with all the major van wiring manufacturers for the Ford Transit in Europe so it was very easy to get hold of unlimited lengths of wiring, connectors, terminals, the proper crimping tools as well as design advice from the wiring designers.

Take a look at the main feed cable from the alternator to the battery on the Magna, this is the size of cable that I am recommending.


Gerry