Help with my plan for a warning system

[pokertramp]

OK so I plan on redoing the dash, putting in aftermarket gauges and such.

Tell me if this is possible...

I will have the gauges back lit with blue led's. I want to make some sort of circuit so that when the oil pressure goes too low or when the temp goes too high, such as warning me that a belt has snapped and the water pump is not turning. When those 2 things happen I want to have RED led's behind the gauges too and they will turn on and the blue will turn off.

This way instead of having only a little dummy light, I have it all in my face and can't miss it. I don't need it for the voltage cause if the power goes down, the lights would dim anyway.

 

[85 Cutlass Brougham]

I believe that someone already makes a set of gauges that way. However, if you want to add some LED's to a existing set of gauges, I would just wire them to ground with the wires from the idiot lights for those circuits. That way, you already have the senders and wiring to the panel. As for how to turn the blue lights off when the senders ground (most senders for idiot lights are normally open, and close to ground only when a certain pressure or temperature is reached) you could use a set of relays. Have them set up in a normally closed configuration so that when no power is applied, they let power flow to the normal blue LED's. When power is applied then, they will open and turn the blue lights off. You could use the same wire that runs your red LED's to turn them off. For a relay board, use the underhood relay bracket off a mid 90's Cavalier, Grand Am, etc. whatever fits your needs. There is a bit more to it than that, but hopefully this gives you an idea.

 

[joe_padavano]

OK so I plan on redoing the dash, putting in aftermarket gauges and such.

Tell me if this is possible...

I will have the gauges back lit with blue led's. I want to make some sort of circuit so that when the oil pressure goes too low or when the temp goes too high, such as warning me that a belt has snapped and the water pump is not turning. When those 2 things happen I want to have RED led's behind the gauges too and they will turn on and the blue will turn off.

This way instead of having only a little dummy light, I have it all in my face and can't miss it. I don't need it for the voltage cause if the power goes down, the lights would dim anyway.

Cool idea. I would imagine that a simple relay would do this. The normally closed contacts would operate the blue lighting and the normally open contacts (that would be closed when the sender went off) would operate the red. I guess the only question would be, can you see the difference in the daytime?