Technical Main Beam Problem

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Technical Main Beam Problem

misfire

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Oct 21, 2007
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Need some help with a problem I have with main beam. Have a bog standard Stilo 1.4 petrol and have recently noticed (now its becoming darker) that my main headlight beam does not work (dip, side, spots and indicators are fine). Have checked the fuses, and have noticed the warning on the dash works, so don't think its the stalk. Think it might be a relay but don't know which is which, can anyone help?
 
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misfire

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Thanks for the replies, but I have checked both the bulbs and they are fine. Have also checked both fuses (14 & 15) in the fusebox by the battery which are also OK. This leads me to believe it might be the relay, but without a wiring diagram I don't even know if the main beam circuit goes through a relay let alone which one!
 
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If the bulbs are ok and the fuses in fine then as you say it must be else where. The car senses monitors all the bulbs by passing a small current (not enough to light the bulb) through them and measures the returning current. I'm not sure but I suspect the stalks are nothing more than switches that the ECU reads before sending a message to a lighting Node.

I don't have access to a wiring diagram but I'm sure Deckchair will be along soon and will be able to post one for you.
 
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misfire

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Anyone seen Deckchair yet, my main beams still aren't working. Did think it might be an idea to remove and check all the relays in the fuse box next to the battery ( as this is where the fuses are and assuming one of those relays is for main beam). Anybody any other ideas? HELP! :confused:
 

Deckchair5

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Hi
OK here's a main beam circuit diagram
main beam headlight circuit.JPG
F10 and F11 are the lights
B1 is the engine bay relays and fuses
M1 is body computer
E50 is the dash warning light
H5 is the switch
main beam headlight circuit fuses and relay.JPG
As both main beams are out I'd go straight for the T2 relay in the engine bay. Feel if it's clicking

Body computer sends an earth out to relay T2 to turn on the headlights

Try the FOLLOW ME lights (pull ind switch towards steering wheel). What happens?
main beam headlight circuit headlights.JPG
If the relay is working and there's power through the fuses F14 and F15 then I'd check for power actually at the lights. A "stab" wire circuit tester is great for this as you can check for power along the wire without having to disconnect anything. As headlights don't get used so much during summer it's not uncommon for a connectors to tarnish/anodise and just need cleaning with contact cleaner to work

Stilo doesn't include the headlight bulbs as part of it's checking "bulb failure" procedure so it's just a case of noticing when they're not working, not too difficult:)

WIRING COLOUR CODES
N= BLACK
B= WHITE
C= ORANGE
M= BROWN
A= LIGHT BLUE
S= PINK
V= GREEN
R= RED
Z= PURPLE
G= YELLOW
H= GREY
L= BLUE
 
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If it aint your bulbs/fuses/switch (I assume you have checked?) then its probably the body computer,done many of these.
 
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misfire

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Thanks for the help Deckchair5 and T14086. Will start working my way through the circuit, now I know the main beams actually go through a relay. To answer your question on the 'follow me home lights', they are working; but they work on the dip beam anyway I thought!(y)
 

Deckchair5

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"To answer your question on the 'follow me home lights', they are working; but they work on the dip beam anyway I thought!"
It's a quick way of testing that the headlight normal flash main beam switch is connected, is working, is talking to and being received by the body computer

What happens when you try to flash the headlights normally?
How have you checked the bulbs?
 
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misfire

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Sorted the problem. Was the relay and must have been just a dodgy contact. Took T2 out as suggested, cleaned it up, put it back in again and up came the main beams. Excellent stuff, many thanks to Deckchair5 and all the others who offered advice.:)
 
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