Hi All,

I’m trying to locate the various relays on a MK8 Fiesta. I checked both fuse boxes (the one in the engine bay and the one behind the glovebox) but couldn’t find any relays, I only found fuses. Is there a specific location for relays?

I’m mainly interested in the front windshield relay(s)

TIA

It’s pretty much all controlled by the BCM. Only maybe relays on the high current circuits like the starter motor. 

15 hours ago, alexp999 said:

It’s pretty much all controlled by the BCM. Only maybe relays on the high current circuits like the starter motor. 

Oh ok I see… I have the attached wiring diagram for the front heated windshield and it says “LH (and RH)Heater Relay”. So I’m guessing it’s not really a relay but rather it is controlled by the BCM?

Where it says 'non-serviceable', that means the relay is part of the fusebox and not replaceable.  

There may be different fuseboxes for different trim levels if your fusebox is missing those relays.

1 hour ago, TomsFocus said:

Where it says 'non-serviceable', that means the relay is part of the fusebox and not replaceable.  

There may be different fuseboxes for different trim levels if your fusebox is missing those relays.

Oh ok I see, thanks for the clarification. My fuse box currently has the 2 fuses (installed from the factory) for the heated windshield (1 for the right side and one for the left side) and I was trying to understand whether I also had the relays, but I’m pretty much stuck because I have no way to verify whether they’re in the fusebox or not. Do you have any advice for that? And do you think the two relays for the heated windshield are in the engine bay fusebox or in the glovebox fusebox?

thanks!

12 minutes ago, Mr_Grapes said:

I have no way to verify whether they’re in the fusebox or not. Do you have any advice for that? And do you think the two relays for the heated windshield are in the engine bay fusebox or in the glovebox fusebox?

As Tom has said the relays will be inside of the Body Control Module (BCM) which is part of the passenger compartment fusebox.

Disconnect the negative battery lead before you begin. Unplug all the connectors from the BCM and completely remove it from the car. If you turn it over you will be able to open up the back of the BCM and see the circuit board inside. They all use the same board (as far as I know) but not all parts are fitted. You may find there will be two empty spaces on the circuit board where the relays should be.

2 minutes ago, unofix said:

As Tom has said the relays will be inside of the Body Control Module (BCM) which is part of the passenger compartment fusebox.

I'm not sure they are inside on these.  It's listed as battery junction box on the diagram above, which sounds like the under bonnet fuse box to me?

1 minute ago, TomsFocus said:

It's listed as battery junction box on the diagram above, which sounds like the under bonnet fuse box to me?

Yes, I'd agree with you. So it must be a case of taking the BJB apart.

1 hour ago, unofix said:

Yes, I'd agree with you. So it must be a case of taking the BJB apart.

Thanks to both of you guys! So I should take apart the engine bay fuse box and check whether there are 2 empty slots on the circuit board itself? And if that’s the case and the two relays are missing, would it be possible in your opinion to get a part number for the two relays and install them? Or should I simply get a new fusebox which has the two relays?

TIA

1 hour ago, Mr_Grapes said:

And if that’s the case and the two relays are missing, would it be possible in your opinion to get a part number for the two relays and install them? Or should I simply get a new fusebox which has the two relays?

You won't be able to get the relays as they are classified as none serviceable.

If they are missing then best option would be to get fusebox from a scrapyard or have a look on eBay

36 minutes ago, unofix said:

You won't be able to get the relays as they as classified as none serviceable.

If they are missing then best option would be to get fusebox from a scrapyard or have a look on eBay

That’s fantastic, thanks a lot for the very useful info!

Will keep you posted on the progress, so that it might turn out useful for someone else as well