Citroen C1, Peugeot 107, 108 & Toyota Aygo Owners Club. (Discount code for CityBugStore: C1OC)

Well I've ordered a new alternator and cleaned all the earthing straps that I can find. Will have to see if that sorts it.

I know its an old forum but I've got the same issue. Got told that it was the alternator so replaced it but the issue continues. Any thoughts?

if I had this problem I would be checking the battery contacts for contamination causing high resistance
take them off clean bright the batter terminots and the inside of the clamps replace tighten
I wouldn't be replacing the alternator at this stage

For the next unsuspected victim that stumble upon "earth" issues.
Earth connections on LHD vehicle.
Front:
- Main earth, top of suspension tower, next to battery visible
- Side of suspension tower, behind battery not visible. Tend to be well corroded!
- Main earth, gearbox, front, 12mm bolt, visible only from under the car
- Side of suspension tower, left side in front of the ECU, visible
- Above ECU, under scuttle panel, not visible. Wiper, wiper motor, scuttle panel with the plastic fairing all must be removed for access.
Except for the mentioned all else are 10 mm.

Rear:
- Side quarter panel, inside, at the level of the rear light cluster, 10mm bolt, not visible.
- Lower left and right sides on the back, under the carpet wall cover, 10mm bolt, not visible.

There's a lot more inside the cabin, etc. But these are the one's in memory!
Action, remove and clean with wire brush, etc. Apply a very light film of Vaseline, also apply some copper grease to the bolt thread, put everything back in place.
A rotary type tool with a small wire brush. Turn cleaning each point, to a few seconds operation. If you have access to one, use it. WEAR SAFETY GLASSES!
This type of tool: https://youtu.be/KbX8VFxCmBo
Cheers