FET or Electronic Relay for Wave Runner

[Dave R]

I'm pretty fair with DIY stuff but electronics are a little over my head. That being said I am trying to replace an OEM fuel gauge on my old SeaDoo. Gauge is no problem but float switch for oil tank is working the opposite way I need. The switch is open when tank is empty and closed when tank is full. I am mounting a new LED next to the new gauge so I would like the warning light to come on when oil runs out. The old OEM gauge must have had a reversing circuit of some kind because it work fine (The old warning light was internal to the gauge). Below is a sketch of how I would do it if I could use an electro-mechanical relay but I can't do that because of the rough pounding the wave runner takes while under power. Is there a brainiac out there that could sketch up what I need to do this? I tried understanding FET's and MOSFET's on the internet but so many variations and some circuits had resistors of unknown values.

 

[Lightium]

Your relay is draw wrong. You need two lines for power to the coil and two lines for the power your trying to switch.

 

[Diver300]

Your relay is draw wrong. You need two lines for power to the coil and two lines for the power your trying to switch.

He has that. The normally closed contacts are in series with the LED.

 

[Diver300]

An automotive relay will be fine in the conditions you get on wave runner. Even if the relay were to bounce occasionally if you really hit a wave hard, the led might light briefly but you wouldn't notice.

The oil splashing around in the tank is more likely to cause an issue.