It's not considered as 'professional' type of fix to incorporate the following suggestion, but I wonder if others privately have thought about doing it :
Namely, scrapping these ground switch lights and putting a washer and bolt. . . that's it . . . No more leaks of this sort to cause a mess.
...
You still end up with oil pressure readings - and provided you watch them a little more often - you're safe and sound without the light.
These items are notorious leakers of oil - they're 'just waiting' to gush oil all over the engine at an inconvenient time.
95% of folks may not like this suggestion - but if you have a fetish for simplicity and reliability - then you may see the merit.
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'82 SC sold
'80 928