Oil pressure gauge doesn't seem to read. It may be that I have an ON/OFF light sensor instead of one that works with a gauge. In any case, I can't get an LED dash light to work. Shouldn't this illuminate if the engine is stopped?

There is a single wire coming off the sender, and the dash light is earthed.

I know the wires for LED's have to be a specific way, because the current only flows one way through them for it to work, and the LED does work when tested.

If there is a single wire on the sender and you think it may be just a switch it will go to earth when the engine is not running so you should be suppling a 12volt supply to the oil pressure LED.

No oil pressure, closed circuit, illuminated LED.

if it is a single wire sender for a gauge the resistance to earth will change with oil pressure.

Gotcha. I'll try putting some (+) to the light.
Thank you!

You're welcome, I hope you get it working.

I struggled to get my oil pressure gauge working to, so you have my sympathy!

Misery loves company. That's why we're here.

How big is the sensor? A sensor for a gauge will be fairly large (1 1/2"ish) diameter whereas a switch for a light will be smaller than the hex to screw it in.

adrian

it is biggish. None of my wiring is going well at this point. Can't get the volt meter to work at all; it either reads 16 volt or nothing or it fries the fuses. I have burnt sixty fuses since I started wiring. It is pretty hard.