Unable to unscrew screw for oil pressure safety switch

[julienrobi3]

Hello! I've just switched from a mechanical fuel pump to an electrical one (works like a charm). However, I want to install a oil pressure safety switch where it is recommended to do so (where the arrow points on the picture: https://www.moyermarineforum.com/for...1&d=1660252652 ).

The problem is that this screw is completely jammed! I've tried adding wd-40, but it won't turn one bit. So l, I thought I had two options: drill the screw or install the switch somewhere else.
Since I really don't want to take the chance of damaging the hole's thread, Im looking for another place to install it. Is this possible at all?
Thanks a lot for your inputs!
Julien

[Al Schober]

I ended up with an oil pressure sender, a mechanical gauge, and the OPSS all mounted on a manifold off engine. The manifold was connected to the fwd port (where the oil pressure sender usually mounts) by an 18" length of grease gun hose (from Home Depot).
Those slotted brass plugs are always a problem. Whenever I went through an engine I replaced them all with plugs with a hex socket. More better!

[ndutton]

My array of oil pressure sensors (OPSS, gauge sender and EWDS switch) are installed the same as Al's, remotely on a bulkhead and connected to the same port behind the flywheel with a pressure rated hose. For the gauge sender and EWDS switch to work the array must have a ground wire connected.

As for the stuck plug, an impact driver will make quick work of it.

[zellerj]

I have had good luck with an impact screwdriver, one that you hit with a hammer and it turns the screwdriver at the same time.

https://www.amazon.com/TEKTON-2910-2-Inch-Manual-7-Piece/dp/B000NPUJYE/ref=asc_df_B000NPUJYE/?tag=hyprod-20&linkCode=df0&hvadid=309802506143&hvpos=&hvnetw=g&hvrand=5033044917044823219&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9015044&hvtargid=pla-384324752796&psc=1

[julienrobi3]

Tbanks everyone for your answers. I followed your advices and installed it where the oil sender is. And eventually I will try using an impact screwdriver to remove the screw if I have an issue with where the switch is now.