Mk7 Both side repeaters not working on power mirrors

[shaz27]

Hello I have a problem both indicators on the power mirrors are not working, checked every fuse nothing gone , I presume this is a wiring problem but where do I look , ps I’ve checked the bulbs to  thank you 

fiesta 09 mk7  

[unofix]

Does the adjustment still work on both mirrors ?

The indicators are controlled from the BCM which is part of the fusebox located behind the glovebox.

Have you got a multi-meter so you can do a few checks ?

[shaz27]

On 11/11/2021 at 4:49 PM, unofix said:

Does the adjustment still work on both mirrors ?

The indicators are controlled from the BCM which is part of the fusebox located behind the glovebox.

Have you got a multi-meter so you can do a few checks ?

Yes mirror adjustments  still work I have a multi meter , where do I start ? Thanks 

[unofix]

Remove each of the side repeaters from the mirror so that you can get to the bulb holders and remove each bulb. Measure the resistance between the outer metal of the bulb holder and the battery negative terminal. Resistance should be only about 1 ohm.

Let me know what value you get

[shaz27]

On 11/11/2021 at 4:49 PM, unofix said:

Does the adjustment still work on both mirrors ?

The indicators are controlled from the BCM which is part of the fusebox located behind the glovebox.

Have you got a multi-meter so you can do a few checks ?

Yes mirror adjustments  still work I have a multi meter , where do I start ? Thanks  both read 1 ohm 🤷‍♀️

[unofix]

Hi Sharon, so if the ground connection is good on both sides then it is reasonable to suspect that there is no 12V positive getting to the lamp when the indicators are on.

The supply and control for the indicators comes from the BCM (body control module) which is part of the fusebox located behind the glovebox. On some models there is an issue with water ingress in to the connectors of the BCM causing corrosion of the pins in the plugs and sockets.

Disconnect the negative lead of the battery before checking but you need to remove all the connectors from the BCM and check for signs of water and/or greenish corrosion of the pins.

[Retired Terry]

I had a similar on my 2014 fiesta on the passenger side , but with mine the electric window did not work either, I took it back to where I purchased the car from and it turned out that there was a problem with the plug and socket had a problem. So the issue was quickly resolved. 

Terry.

[shaz27]

On 11/25/2021 at 2:03 PM, unofix said:

Hi Sharon, so if the ground connection is good on both sides then it is reasonable to suspect that there is no 12V positive getting to the lamp when the indicators are on.

The supply and control for the indicators comes from the BCM (body control module) which is part of the fusebox located behind the glovebox. On some models there is an issue with water ingress in to the connectors of the BCM causing corrosion of the pins in the plugs and sockets.

Disconnect the negative lead of the battery before checking but you need to remove all the connectors from the BCM and check for signs of water and/or greenish corrosion of the pins.

Right now the adjustments have stopped working and all the fuses , plugs etc are clean in the fuse box , so I think there must be a wiring problem somewhere, would it be in the door panel? Would that control both sides ? The mirrors itself go in and out but that is all they do 

[unofix]

Each front door has a "door control module" inside the door itself. Normally using FORScan any problem with these would show up a DTC. Also the doors are to a large part independent of each other so I would think it unlikely that the DDM and PDM would be at fault.

I suspect the problem lies with the BCM. I think you will have to fully remove the fusebox and BCM from behind the glovebox and then take the plastic cover off the back to check for problems.