What is the best wire I should splice into for the gauge positive?

I have the gauge mounted in the middle of dashboard area

 

 

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When you say that is mounted in the middle of the dashboard, is it replacing one of the 3 gauges? A picture would help.

Sorry about the description it was vague. it’s down where the air/heat controls are located. I removed those since I no longer run air/heat so I made a blanking plate for it it’s an AEM gauge I was thinking maybe a wire from the stereo harness

 

 

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How many amps does it pull?  Might be best to just run a new wire to the battery for a relay, then tap in to a wire that functions when you want it to to control the relay.  Always hot, or key at Acc. or Run.

Instructions say connect to a switched 10-18 volt power source with a 10amp fuse

 

I am thinking cigarette lighter now as the source for power

 

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Looks like a good one.  Is the cig lighter switched though?  I seem to recall older cars where it was always powered.  It's right next to the horn and dome light which are always powered.  No biggy, you can add your own switch.

I know on the 240Z and 260Z the cigarette lighter has constant power. I will check the 78 FSM to see if it's the same.

What is the brand and part number of the FAM? There may be something online saying how much power it draws.

Ok just found more the gauge is 1.3amps
Sensor is 1.2amps at 12v it says
It’s an AEM 30-4110


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If I recall properly the radio is switched power my car also doesn’t have that installed anymore but I can test that out tonight


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If you want to use the old stereo power, look for a blue wire. There are actually two that you could use. One is on a 6 wire connector (stereo), and the other is on a 3 wire connector (antenna).

Hey that’s great I will check that out tonight and post back if it’s working


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Ok yep the blue line for the radio worked for switched power and there were two black lines one didn’t seem to go to ground maybe to a speaker. The other was ground and it works perfect now.


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