I've started to tackle some long-ignored dashboard wiring issues and it's got me thinking... Is there a good way to build your own "idiot lights"? I would never trade gauges, especially original ones, for just a light, but it'd be nice to have something more attention-getting in the event of a problem with oil pressure, temperature, etc. In a computerless car, there's got to be some way to do this, but it might be different for each gauge - Some kind of pressure switch for the oil light, some other kind of switch for the temperature, etc. For what it's worth, I'd be doing this on a 6V negative ground system. Anyone attempted anything like this? If I do these, I could wire them up as separate lights or one centralized "check engine" idiot light. Might even label it "Check gauges, you idiot"...
Idiot lights are controlled by switches that don't care about voltage. I'd use a volt guage for the exception. Oil pressure switch at ___ psi, water temp switch at ____degrees. Add wiring and chosen lighting.
Power from ign to light to sender if I remember correct. send goes to ground and the light lights up. What I don't know is if the 6 volt will work thru a 12 sender. I have an old Hudson dash that has idiot lights so maybe you could find a 6 v sender for the oil. Athis moment I cannot tell you how to wire the gen. Idiot light. Modem is getting very sleepy......
You can use the same light for oil pressure and temperature. Either switch grounds and the light comes on.
I got some small LED's from Radio shack, was thinking along your same train of thought, was also going to use green ones for turn indicators, but could not find a blue one for high beam indicator.
How might one add a temperature switch? Temperature probes are normally in the block/water jacket, as is the case with the current gauge. Is it possible to mount something in a coolant line somehow to avoid drilling a new hole into the block?
Beautiful. Thanks! I've wanted to add a "second opinion" temp gauge anyway, this gives me a way to do that, with or without the idiot light.
having a temp sender in the radiator hose won't really do what you want, will it? You want to know when the cylinder head is overheated because there's not enough coolant flow...think about what causes this, and what the temp would be in the radiator hose. But yeah, I have idiot lights in my 55 for oil and generator, the oil pressure sender goes on at 20 psi. I don't have a volt or amp meter. I have a temp gage, but no light for it, since I can keep an eye on it pretty easily.
If the looks of the guage arent really important, you could use a Murphy guage and use the guage itself as the ground for the light. I used to do this several years ago when I was into roundy-round. That way you really didnt have to look at the guage, just watch for the light to come on !!
Touché. Taken especially well by someone who is on their fifth head gasket on their old daily driver (a '91 Plymouth).
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