RX400h - rear fog lights not working - relay location

[Richard 86]

Hi, my rear fog light appear to have stopped working and I have an MOT coming up soon.

Checked the rear left bulb. Worked fine.

Checked 7.5amp fuse in passenger footwell. All good.

Does anybody know where the relay is? I've opened the relay boxes in the engine bay and non are marked as fog lights.

User manual contains no useful info.

The indicator on the dash doesn't doesn't illuminate if that narrows the problem down.

I'm only using with dipped lights.

Thanks 

 

[Herbie]

This is a mixture of drawings for both left-hand and right-hand drive cars but you should be able to get enough information from them to give you a fighting chance:

[Richard 86]

That's for the diagrams. Just had a go at lying on my back in the footwell to find that rely box no.  1 and it's hiding.

I'll try in the morning when there's light and hopefully no rain.

I wish car makers would insist on hiding fuses and relays above footwells. It's just rude.

[Richard 86]

I've had another look today.

I can only find two small blue relays above the passenger footwell. Right behind the fuses.

One is definitely the front fogs.

Identified by following the clicking sound. 

When I pull this relay, the dash still illuminates to say the front fogs should be on.

I swapped the two blue relays round.

No change.

There is no click to be heard when switching on the rear relays and no illuminating dash light.

This leads me to believe it's either a faulty switch.

Or.

The ECU which must tell the rear fog lights they can turn on is not passing the signal on.

Does the lack of dash light illuminating narrow this down?

[Richard 86]

Ok update.

I've been yanking on the wrong relays.

I hard wired the terminals on the blue right relay visible from the footwell and the taillights came on.

So after removing the glove box discovered another blue relay much higher up.

See pic.

But it's impossible to reach without removing the whole fusebox and ECUs.

Is there another way to get this blue relay I'm not thinking of?

 

[Richard 86]

Ok, update.

Unplugged the fuse box in the passenger footwell.

Managed to drop the relays box enough so I can remove the relays.

After plugging everything back into fuse box I started jumping the relays.

Turns out, of the three relays it's the middle one. Small blue thing.

Rear fog lights both came on.

FYI, grey one is the blower fan if of any use to anyone.

Relay seems to work fine.

So now just need to work out why the relay isn't being triggered.

Ordered a second hand stalk switch thingy from eBay to check if that's the issue.

As the mot is fast approaching might just wire my own little switch for now.

 

[Richard 86]

Well overdue update

Temporary switch for MOT worked fine.

Swapped for stalk switches for a second hand unit and all is fine now.

[Jonaszen]

Hi, is the rear foglight relay the one that sits right next to the front foglight relay?

[Richard 86]

We're going back it bit now, but I think they are on different relay boards.

The relay board with the two blue relays pictured above is quite easy to get to and I think had the front relay on it. But not the rear.

I had to remove this relay board just to see the much higher and smaller relay board that had the rear fog relay on it. It was a pain to get to.