I’ve been having a similar problem on my 1979 CB750L. I changed all the lights to led’s, but my oil pressure light stays on. I bought a new oil pressure switch, and I have enough oil and oil pressure. After reading this forum, I think I need a resistor, but I’m not sure where exactly. Do I need to put one by the stop light warning unit, down by the oil pressure switch, or in line with the taillights? Any help would be great!