Technical No dip beam

[paullap]

Hi I have a 2007 Grand Punto, and I have no dip beam, all other lights work. Looking at the wiring diagram it is earth switched from the body control module. I have traced it back as far as the fire wall and if I probe the wire by the bulk head and earth it out the dip beam comes on. The stalk light switch has been changed with one from the scrappy. But I want to confirm the problem. and to do this I need to access the wires going in and out of the body control module, ( I am pretty sure this is where the problem is) It telling me the main wire that will feed the switch is D51 ant the body control module and when the dip beam is switched on pin D38.

Can anyone tell me I can identify plug D on the body control module so I can probe the wires to see what is happening.

And also what readings should I get on each wire, I would think some sort of voltage on pin D51 Key on, and the some voltage on pin D38 when dipped beam is switched on . If it is switching OK to the body control module, all i Have left is the wiring from the body control module to the fire wall. if that is OK then it has to be the body control module?.

Thanks Paul

 

[Bernievarian]

Hi Paul,

the BCM does not earth switch the dipped beam, it is a positive control.
Anyway, here's the diagram where you can locate the connectors and pins... Relay T3 might be the culprit, unless both fuses are blown!

BRs, Bernie

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[paullap]

Hi Bernie, Just glancing at this, This is not the wiring diagram that i have, and mine is earth switched. because at the relay I have 2 permanent 12v feeds at the relay. and if I earth the wire that feeds the switch side of the relay the dipped lights come on. I will try to find out how I can copy the wiring diagram from autodata and show you.

Thanks for the help


Paul

 

[Bernievarian]

Hi Paul,

from what I know, modern cars are never negative switched on the power side. But the command side uses this type of command extensively, as well as for the sensors.
So according to the schematic (I got from eLearn), if you earth pin 86, the relay would switch the positive to the bulbs. Curious to see the diagram you had from autodata...

BRs, Bernie

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[paullap]

Hi Bernie, I have tried to attach the drawing, lets see what happens. If you can see it, I will give you further details. I could send you a PDF file if you prefer.

 

[paullap]

Ok I think that worked. Far right hand corner S6 is the combination switch and S 4 is dip Beam, When switch on it comes from pin 2 on the switch and goes to D37 on the body control module. relay Plate X28-1 Relay K41 if I earth out pin 86 the dip beam comes on. so the body control module is giving the relay the earth to pull in the coil to send live to the dip beam, So if it is sending an earth to the coil is this not earth switched, or am I not explaining this correct.

Paul

 

[Bernievarian]

The RELAY is earth driven (switched), but the DIP BEAM is positive controlled ...

At least your test means the relay is ok, since if you power its coil it switches ON, so either the BCM or the stalk switch or related wiring/connection doesn't do his job correctly ...

BRs, Bernie

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[paullap]

Hi Bernie, Yes that is correct, I just did not explain it properly, If I earth the wire from the relay to the BCM. the dip beam works. I need to test the input from the stalk and and the output from the bcm. My drawing is telling me it is plug D and I am pretty sure it is the one at the back of the BCM, Do you have any info on the BCM plugs?.

Also I have the E learn disc but I can find any wiring diagrams on my disc, So i am not sure i have a good one.


Paul

 

[Bernievarian]

Hi Paul, look at the diagramm I sent, there is the sketch of the BCM and its connectors...

BRs, Bernie

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[paullap]

Re: No dip beam"""fixed"""

Hi Bernie, I finally got to the problem, I checked the wire coming out from the BCM, this is a 4 volt pull down design, when i operate the dip beam switch, it was switching from 4 volts to 0.0 volts earth, so that proves the BCM was not the problem. I then checked that same wire where it goes to the fuse board. """"12volts"""" the wire must be shorted to battery 12 volts in the loom. so I cut the wire from the BCM and then where it goes in to the fuse board and put a new piece of wire in and all works perfect.



Another mystery solved


Thanks again for the help


Paul

 

[Bernievarian]

Re: No dip beam"""fixed"""

Job well done Paul, and thank you for the update !!

I'd recommend though to find where's this 12V "interconnection" since it might impede on other functions of the car ...

BRs, Bernie