V70: Electrical - Rear fog lights

mark2cars · Oct 25th, 2016, 18:27

A simple questions but hard to find answer! Having just replaced the dipped beam bubs with some nice bright ones for winter I thought i'd tackle the rear fog lights...
Q. The rear fog light section of the tailgate cluster was about 1/4 full of water! This has obviously blown the fuse for the rear fog lights as it gives the bulbs a good shower every time the tailgate is opened! There is no faint light on the rear fog switch when it is pressed and no fog lights come on. So I searched the manual several times (pp238 - 241) for the location of the fuse with no luck. Searched this forum and others. Front fogs are listed but not the rear?! From previous mk2 V70 where I had to change some relays in the boot for the brake lights I would have thought they were located there, but no..Any idea which fuse it is please?
Thanks, Mark

V70 2008 D5.

mark2cars · Oct 27th, 2016, 18:42

I guess no-one else's had this problem - I'll test them all then, if I find will let you know...

apersson850 · Oct 28th, 2016, 20:57

There is no separate fuse for the rear fog light. It is driven directly by the CEM, which usually monitors its outputs for shorts and similar. Thus it's probably the CEM that has cancelled the power to the rear fog light due to the water ingress.

The CEM is fused by 11A/1 and 11A/2, but to remove them will probably result in a major fault.

mark2cars · Oct 29th, 2016, 11:42

Thanks !
It seems that having removed the water and having it dry (ish) for a couple of days, the fog light has come back to life without changing anything - not even the bulb!

Tatsfield · Oct 29th, 2016, 22:44

All you need to do now is to stop it filling up with water again!

Oct 25th, 2016, 18:27	#1
mark2cars New Member Last Online: Mar 14th, 2020 14:28 Join Date: Apr 2012 Location: Porthmadog	Rear fog lights A simple questions but hard to find answer! Having just replaced the dipped beam bubs with some nice bright ones for winter I thought i'd tackle the rear fog lights... Q. The rear fog light section of the tailgate cluster was about 1/4 full of water! This has obviously blown the fuse for the rear fog lights as it gives the bulbs a good shower every time the tailgate is opened! There is no faint light on the rear fog switch when it is pressed and no fog lights come on. So I searched the manual several times (pp238 - 241) for the location of the fuse with no luck. Searched this forum and others. Front fogs are listed but not the rear?! From previous mk2 V70 where I had to change some relays in the boot for the brake lights I would have thought they were located there, but no..Any idea which fuse it is please? Thanks, Mark V70 2008 D5.

Oct 27th, 2016, 18:42	#2
mark2cars New Member Last Online: Mar 14th, 2020 14:28 Join Date: Apr 2012 Location: Porthmadog	Rear Fog light fuse I guess no-one else's had this problem - I'll test them all then, if I find will let you know...

Oct 28th, 2016, 20:57	#3
apersson850 Premier Member Last Online: Apr 22nd, 2024 14:08 Join Date: Jul 2011 Location: Traryd View Photos By: apersson850	There is no separate fuse for the rear fog light. It is driven directly by the CEM, which usually monitors its outputs for shorts and similar. Thus it's probably the CEM that has cancelled the power to the rear fog light due to the water ingress. The CEM is fused by 11A/1 and 11A/2, but to remove them will probably result in a major fault. Last edited by apersson850; Oct 28th, 2016 at 20:59.

Oct 29th, 2016, 22:44	#5
Tatsfield Premier Member Last Online: Yesterday 11:02 Join Date: Nov 2015 Location: Poole	All you need to do now is to stop it filling up with water again! __________________ 2012 XC70 SE Lux Polestar 230 bhp D5 Auto Oyster Grey

Oct 29th, 2016, 11:42	#4
mark2cars New Member Last Online: Mar 14th, 2020 14:28 Join Date: Apr 2012 Location: Porthmadog	Thanks ! It seems that having removed the water and having it dry (ish) for a couple of days, the fog light has come back to life without changing anything - not even the bulb!

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