How do you wire in a new oil level light

[DeanBrantley]

So I went ahead and cut open my gas gauge to see what made it tick, it was broke anyways. Bought a new one for $15 not bad. These are the pics. The problem: I want to hook up a low oil level light just like the old one. So I bought a 14v led to mount above the gauge. The oil level sensor looks like it is a straight on/off type switch so it seems that the light should hook like this. LIGHT: Red/positive to the purple power lead on gauge. LIGHT: black/neg to blue lead going to oil level switch. OIL SENSOR WIRE: blue black wire to gauge ground (black). Now if we look at the circuit board we see how the old attached light was mounted on the boardhere are other pics showing the board and my diagram. I hope this would be the correct way to wire the light, now what about that pesky resistor??

 

[Dr Honda]

The original LED is only a ~3v unit. SO... the resistor is to clip current/voltage, so it doesn't eat itself. Since you have a 12v LED... it can take the power directly. BUT, the switch in the tank is small. SO... make sure the current load isn't too much for it. (I'll assume the LED you have already has limiting built into it)

 

[DeanBrantley]

Thanks Doc Honda, you are the best. I guess the question is this. If the LED is 3v and the resistor must limit v(who knows the amperage) if I hook a 12v LED into the circuit can the oil sensor handle the currant/voltage?? I can't find anything anywhere about the specs on the oil level sensor's capacity to handle either one. Should we just go have Tequila shots somewhere. Oh wait... my wife said I stopped drinking since I have this very calming pass-time.....BOATS

 

[Fat Tony]

The resistor is a current limiting resistor, it also works to as a voltage divider to limit the voltage to the LED. If you remove the resistor, current in the circuit should be slightly less due to the efficiency of the circuit increasing without the resistor, it may even be slightly less or more depending on the resistance of the replacement LED, but the current draw will be in the milliamp range. If the LED is a 1/4 watt then the current draw will be around 20 milliamps...

 

[DeanBrantley]

I have a 12v and 14v LED. So I wired in the 14v one, neg to gauge ground and positive to blue lead to the oil level switch, no resistor. I'll apply power in the morning and let you know if I smoke the LED or sensor

 

[DeanBrantley]

Didn't work, now I shined a flashlight thru the board and saw the entire left leg, coming out of the light and down to what appears to be contact 3 is a dead end lead and that 3,4 and 7 are connected. I also saw the hot, purple, wire is connected to the Lt blue at A, I'll splice them together and try again

 

[DeanBrantley]

Nope, that didn't work either. So I wired in the original 3v LED with its resistor, Lt Blue oil sensor lead and hot purple leads to resistor and blk to ground, just like on the circuit board. Light stays on continuously, so now I give up. I disconnected it. Electrons are funny!

 

[tkarvelis]

Try turning the led around. They have polarity. The longer leg on the led is the anode or positive. The shorter leg on the led is the cathode or negative.

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