fog light

[waterman]

hi all
i have a 2017 sprinter van 319 v6 4wd. just been for mot and rear fog not working
light comes on beside switch, bulb is fine but no power to rear fog light, am at a loss to why as never use it
thanks

 

[markjay]

Welcome.

From memory, the rear fog light can only be switch on if the headlamps are on?

 

[waterman]

Welcome.

From memory, the rear fog light can only be switch on if the headlamps are on?

Hi, Lights are on as little light for fog comes on beside switch

 

[BTB 500]

It presumably worked before otherwise it would have been an MOT fail previously. I would check that the contacts on the bulb & holder are good & clean (no corrosion etc.), also the connections from the loom to bulb holder (try wiggling things with the rear fog switched on). Next stage would be using a meter to check for voltage there. Oh and check the fuses just in case, although I doubt there will be one just for the rear foglight. Do the front light units include foglights, and if so do those work?

Nice spec. van, btw

 

[BTB 500]

From memory, the rear fog light can only be switch on if the headlamps are on?

Not sure if a 2017 Sprinter is the same as our Vito, but on that you can only pull the knob out to activate the front and then rear fogs if it's already been turned to the sidelight (I think) or headlight position. You can't do it in any other position (including auto, where the knob is normally left all the time).

 

[Diesel Benz]

Does it have a socket for trailer lights? Often the switch there misbehaves. Rear fog is supposed to be switched off when a trailer is attached.

 

[BTB 500]

Does it have a socket for trailer lights? Often the switch there misbehaves. Rear fog is supposed to be switched off when a trailer is attached.

Interesting idea, although I thought this was done electronically when a connection was detected (reversing lights and rear parking sensors should also be disabled when hitched up)?

 

[waterman]

thanks all for reply,
no front fogs, warning on dash says no fog light , have removed multi plug on rear light and tested for a supply, none there. it does have a trailer sock that was factor fit with towbar.
cant say weathewr or not was working for last mot as was not there,
is there a relay anywhere for it
thanks
darren

 

[BTB 500]

Doubt there'd be a relay for rear fogs ... it's normally just a single bulb (offside). Sounds like it could be an issue with the switch or (less likely) loom. But also have a look at the trailer socket ... pretty sure mine (also factory fit, but on a Vito) doesn't incorporate any kind of mechanical switch, but you never know. Surprised a Sprinter doesn't have front fogs, they are just extra bulbs in the cluster on the Vito:

 

[waterman]

had some one else say could be switch in the trailer socket will have a look this weekend, front fog would need to have different switch as no position on mine for front ones
thanks