Why not connect main lights in paralell?? Original in my car is serial....

[olehoholm]

I'm currently installing a relay, activated by the ignition, to turn on the main lights whenever the car is running. When I cut the + wire for the right light and connected it to the relay instead, both of the lights came on. Ding... they're connected in serieal.. of course! ... or is it room for an "of course" here? I mean... as known, bulbs connected in serial will demand the double from the generator to work properly... Resulting in my lights going on dim.

My question is: Will I damage anything if I connect the bulbs directly in paralell through this relay? The bulbs will glow the double and therefore get more hot... they'll demand the double of the generator... anything?

Does the computer in the car monitor lights? Will this ev. get a caramell if I connects the lights this way?

[Javier]

with the electrical system not having any wiring diagram nor clue of the system operation. No way the head lamps are wired in series, unless someone damaged your car electrical system before you.

The lamps (each of them) are not only not connected in series, but are feed by full 12 Vdc trough an independent fuse each (F10 for left, F11 for right). If your car has no LKM, there is a Head light relay feeding a single yellow wire to the front fuse box, and from there, independent wires, Yellow/Green for left from F10, and Yellow/Blue for right from F11, feed the lamps. If you TAP any of those two wires with power, yes you light up both lamps, if you cut the yellow wire to the fuse box and feed the proper end with power, yes you light up both lamps. It doesn't mean they are in series. If you cut the Yellow/Green or the Yellow/Blue wire and manage to feed both lamps, there is something wrong with your car, you better check it.

With LKM cars, the LKM itself have the relay, but there is no way that feeding one lamp will feed the other by retro-feeding unless lamps are on.

This link may help you understand the Headlights circuit in no LKM cars.

http://www.carsoft.ru/avtorepair/bmw_e34/0670.3/index.html

I do not pretend to be rude nor lecture you, even more, I feel this strong determination "TO DO" no matter knowledge or background, is what get mankind to the moon, but prefer you to know what you are doing.

Javier

[ukm5]

a more sensible option would be to have the relays switch the light switch itself rather then directly switch the bulbs on

therefore your not interfeering with the cars circuits, it just acts like you have switched the lights on

[olehoholm]

Well.. I was tired... if that's any excuse of the post I made. How I could write some of the conlusions amazes me! :P

But the day after I wrote the message in full confusion, I downloaded the haynes book (I also own one but it's packed away so it's not buff :)) and I read it twice. Still I couldn't figure out what I had done wrong but at last, now I understand what it was: This is the FIRST time ever I've seen that the ground wire has been brown and + has been yellow with a green stripe through it!!! So I shortcircuited the battery... Things like this happens... what is it else we have fuses for? :)

After my first post it's embarrasing to tell that I, until recently, acctually worked as an avionic-technician and are now doing bachelour for engeneering in elektro.... But it's also the reason I dared to do it. I know lightning systems well and are generally well equipt with knowledge of el-systems. Now I've connected the battery trough the new relay directly to the lamp when the ignition goes on. But still... it's only the headligts, the rear lights remains. But... yeah... some other day... not now! :)

Ole Bjørn

[ukm5]

doing that is a very good way to damage your LKM

you should have just wired a relay to switch on the light switch therefore using the original lighting circuit and also you would be working with low power switching rather than having to use heavy duty extra wiring and going to so much extra work

[olehoholm]

All theese shortcuts I keep jumping over... That's a great idea... probably what you meant in your first post too? I think the thought of connecting the switch has crossed my mind, but I didn't quite catch it until now.

I'll se on that... I still have to find the rear lights too you know.

Thanx a lot!

Ole Bjørn

[ukm5]

and you worked in avionics....ill never fly again!!

[olehoholm]

tjihi... Cars and planes are two different worlds. On planes we'd never do anything without having the proper documentation and education. Car's electronics are not one of my skills :) But I'd claim I didn't do any hazardious actions... It's only the conclusions in my first post I'm very embarased by.

Anyway... I wouldn't like to leave the impression that the aviation business is anything like modifying or repairing cars. The level of accurate and trustworthy work is very high. I'd fly anytime!

(Just in case you meant or anybody else read your last post... ;) )

[Javier]

Javier

[olehoholm]

Which thread???

[Javier]

http://www.bimmer.info/forum/showthread.php?t=9505

Javier