Volkswagen Jettas & Golfs (Mk II’s) are well known for having corrosion problems in regards to their fuse panel boxes. This solution may work for your car. I make no guarantees and I recommend you do this only AS A LAST RESORT. This worked for my Jetta. This method cleaned the corrosion rot out of my fuse panel box.
- Disconnect car battery.
- Remove your fuse panel – vehicles will vary by make, model & type
- Remove all fuses, relays, and anything else attached (make a note where you took what off so you can put it back in place).
- Take the fuse panel box and place it in a plastic container that is adequate in size.
- Pour CLR (Jelmar brand) or any other similar product into the container until the fun panel box is submerged. Cover with lid.
- Wait about 2 hours occasional shaking or moving the fuse panel around in the liquid. You may need to wait longer depending on the amount of corrosion on the fuse panel box. In my case, I left the fuse panel submerged for 10 hours (overnight).
- Remove fuse panel box from the liquid and rinse thoroughly with water till you are certain the cleaning fluid has been removed from the fuse panel box.
- Dry the fuse panel box as thoroughly as you can. I found that a blow dryer worked pretty good.
- Once the fuse panel box is dry, re-install it in your car.
CLR is a rugged cleaning fluid. You should be able to recycle it for another use or two by pouring it back into its original container for future use.
My fuse panel box would not let my backup lights, my turn signals, or horn work. After the above process, all worked fine again. Please note that I did not need to use any kind of hard labour to clean any of the contacts. The pictures below show the obvious signs of corrosion. There was more within the fuse panel box, I’m sure.