Technical Oil pressure switch earth corrosion

[euroben]

I have seen on here that people have had issues with a poor earth on the oil pressure switch/sensor. I have managed to squeeze my phone down to see mine on camera and it is a bit corroded. I also have a yellow triangle that I don’t seem to be able to get rid of. What I can’t see is how best to access this to clean it off. I don’t see a good way from above. How have people accessed this on theirs? Is it best from underneath. I can’t see without taking the under guard off.

 

[Big gerry]

I had the dreaded yellow triangle of doom for the same problem my mechanic worked on it from above he attached a wire to the oil pressure switch then attached the other end to a random bolt of your choice out went the light he told me to repair it right I would need to replace the filter housing so we tried this and worked

 

[euroben]

I had the dreaded yellow triangle of doom for the same problem my mechanic worked on it from above he attached a wire to the oil pressure switch then attached the other end to a random bolt of your choice out went the light he told me to repair it right I would need to replace the filter housing so we tried this and worked

There seems to be very limited access from above, at least for me with fairly large hands. I can just about get my hand down there but I am then relying on what I can feel rather than what I can see.