Technical Both dipped beam headlights not working (Fiat Ducato 2014 X250)

[pebble99]

The side lights and the high beam work ok. The fuses are fine and I will check the bulbs once it stops raining, but I doubt it's the bulbs as both are not working. Next thing to check is the relay and then the steering wheel stick headlight switch. I have enclosed a picture of the interior fuse box which is located near the drivers door. Does anyone have a diagram of my fuse box which I think is the MK3 version of the BSI/BCM (Fiat Ducato 2014 X250 model) to show where the dipped beam fuse is located and also how to remove the metal casing which covers the left and right sides of the fuse box?

Also noticed that the hazard warning light switch in the center console does not flash (the exterior hazards lights all flash though). I wonder whether this is connected and maybe this unit that contains the hazard switch also controls the dipped beam?

 

[rayc]

any help?

 

[pebble99]

any help?

My interior fuse box to the right of the steering wheel is different to this. It must be a later version of the x250 BSI/BCM (mk3)

 

[rayc]

My interior fuse box to the right of the steering wheel is different to this. It must be a later version of the x250 BSI/BCM (mk3)

I have attached the fuse box info for later variants. The dipped beams are F12 & F13 in the cab fuse box. Note these fuses feed the output to each lamp separately from the common relay. The relay is operated by an output of the BCM

 

[pebble99]

I have attached the fuse box info for later variants. The dipped beams are F12 & F13 in the cab fuse box. Note these fuses feed the output to each lamp separately from the common relay. The relay is operated by an output of the BCM

Thanks. I have already checked fuses F12 and F13 and all ok. What I am trying to find out is the location of the relay for the dipped beam on the BCM. I can hear it click on and off when I toggle the switch on the headlight stick so does that mean the fuse is definitely working and the issue is with something else?

 

[rayc]

Thanks. I have already checked fuses F12 and F13 and all ok. What I am trying to find out is the location of the relay for the dipped beam on the BCM. I can hear it click on and off when I toggle the switch on the headlight stick so does that mean the fuse is definitely working and the issue is with something else?

In earlier models the relay was part of the fuse box and easy to locate. I guess that if you can hear the relay click in response to the stalk activation, i.e. lights on switching between main and dipped beams, that the BCM is giving an output to the relay. Can you monitor the voltage at each of the fuses to ascertain whether volts is applied when dipped beam selected. [ Do not get confused as the relay that you can hear operating may be the Main Beam one and not the dipped beam one.] I cannot help further as I have never taken the later fuse box apart to locate the relays.

 

[pebble99]

In earlier models the relay was part of the fuse box and easy to locate. I guess that if you can hear the relay click in response to the stalk activation, i.e. lights on switching between main and dipped beams, that the BCM is giving an output to the relay. Can you monitor the voltage at each of the fuses to ascertain whether volts is applied when dipped beam selected. [ Do not get confused as the relay that you can hear operating may be the Main Beam one and not the dipped beam one.] I cannot help further as I have never taken the later fuse box apart to locate the relays.

Hi, thanks for the info. To measure the voltage on one of the dipped beam fuses, would I simply put the +ve and -ve probes across the top section of the fuse or should I remove the fuse and measure across the terminals?

 

[rayc]

Hi, thanks for the info. To measure the voltage on one of the dipped beam fuses, would I simply put the +ve and -ve probes across the top section of the fuse or should I remove the fuse and measure across the terminals?

Negative meter lead to chassis, positive lead to the fuse. If the fuse is good it will not matter which end you put it to

 

[pebble99]

Negative meter lead to chassis, positive lead to the fuse. If the fuse is good it will not matter which end you put it to

Hi, the fuses are definitely ok as I have swapped them out and no difference. I was wondering whether by checking the voltage at the fuse with the headlight switch on, I can check whether voltage is actually reaching the bulb (or will there be a voltage reading at the fuse regardless of whether the light is switched on?)

 

[pebble99]

all sorted...it ended up being both bulbs blown!