water temp gauge installation

[challenger_affair]

I have an electrical autometer temp gauge I want to install and don't know where to tap into a power source for the gauge or for the light.  Also, where should I ground the gauge and light? 

I need remedial instruction, like, find the orange wire connecting to...  or something like that.  I'm sure there are different ways to do it, but I just need something basic that will work.  Thanks! 

Link to gauge
http://www.autometer.com/2-water-temp-100-250-f-sse-z-series.html

[challenger_affair]

I should add this is on a 70 challenger with a rally dash. 

[FY1Cuda]

There are orange wires under the dash.  One's going to the radio for the light behind the dial. One is going to your console (if automatic) for the shifter plate, and another is going to the light bar over the instruments. You can probably find one or two of them plugged into a three-hole tap.  If you have the right sized bullet connector, you can tap into where the orange wires are plugged into.  Otherwise, splice into an orange wire and when you turn the lights on, your new meter will light up with the instrument lights.

[Racer57]

Fasten ground wire to one of the gauge mount screws. Take the other wire and start touching fuse ends on your fuse block. When you find one that works, stick the end of the wire into it. OR, if you prefer to not do it like when we were younger, do like FY1cuda says. 

[challenger_affair]

Thanks guys, that makes sense for the gauge light    How about power source for the gauge itself? 

[Racer57]

Thanks guys, that makes sense for the gauge light    How about power source for the gauge itself?

No electrical hook up needed. Its reading the temp from the probe.

[challenger_affair]

There is a temp sender but its an electrical gauge and the instructions specifically state it needs to be connected to a switched 12v power source.    

[Racer57]

There is a temp sender but its an electrical gauge and the instructions specifically state it needs to be connected to a switched 12v power source.   

Using the wire for the gauge light, place the end on a fuse until you find one that turns on/off which the key. That will tell you which one is switched.

Connect the gauge light wire with a wire going to the gauge temp wire so that it looks like a "Y".  Two into one.

Splice your wire into the wire coming out of the fuse panel that you found to be switched.

[challenger_affair]

Thanks for those suggestions, I think that puts me on the right track for the wiring 

Unfortunately, there's a problem with the fit of the sender.  The diameter of the actual sensor part that sticks into the housing past the threads is about 0.02 in larger than the stock sensor   

Does anyone know if i can use the stock sender with the new gauge? Or can the new sender be milled down by a machinist so it fits? this might not be a good option but i'm just wondering... 

[FY1Cuda]

You can probably use the stock sender without any problem.

[challenger_affair]

Just to follow up, I spoke with Autometer today was told the gauge is not calibrated for the stock sender, so that would not be an option...  However, it turns out they have a sender with a short probe that looks like it will do the trick.  I hope to have it in hand Friday...