Key Ignition Wire +12 volt

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Oct 30, 2014 | 04:31 PM

1batt4u

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Key Ignition Wire +12 volt

Hi all,

I just bought 2 autometer gauges, Fuel Pressure Gauge and a Boost/Vacuum gauge for the center A/C vents. Gonna buy a third gauge soon for my 2000 Trans Am LS1.

They are digital not mechanical.

Here is the the Boost/Vacuum gauge I bought #5959:

Auto Meter - Gauges

My question is, the Installation guide writes that the Red + wire should be connected to a +12 volt source that maintains power during engine cranking.

I was gonna connect to the radio until I read about this. The radio turn off when cranking.

Where can I connect that doesn't turn off while cranking? Or is there a direct wire coming from the key ignition that I can connect to?

Here is a picture of the wires from the steering column.

Thank you!!

Oct 30, 2014 | 05:07 PM

Spartan7

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The radio has both 12v hot and 12v switched sources to tap into. Or, take them right off the I/P fuse block on the driver side of the dash.

Nov 1, 2014 | 07:02 PM

1batt4u

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Quote:

Originally Posted by Spartan7

The radio has both 12v hot and 12v switched sources to tap into. Or, take them right off the I/P fuse block on the driver side of the dash.

I believe the 12v switched works along with the crank, meaning the radio shuts off while cranking, I need constant 12v while cranking, not to shut off.

Nov 1, 2014 | 07:14 PM

1 FMF

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From: CT

without looking at the wiring diagram in the service manual to be sure, i believe the radio is connected with or thru the BCM, has to do with the alarm and all that crap. so i would be careful tapping off any radio power wires because poewr might drop out during engine cranking.

but given your gauges, does that really matter? your instructions mention it but i can't see how power going off during cranking then coming back on would affect the guages and their purpose. not like you need to measure boost/vacuum during that 200 rpm of engine cranking.

my recommendation would be to tap off the fuse block that's under the hood. there you can tap off one of the wires that go to the 40A IGN fuses, and use an inline fuse right after the fuse box so that if for some reason your gauges or wiring pulls more than 1 or 2 amps it blows your inline fuse and kills just your gauges, and doesn't blow the IGN fuse and kill the engine while you are driving. the bad part about this is you would have to run a wire from there through firewall into cabin. or you might be able to tap off the fuse panel that's inside the cabin... if there is one i don't remember at the moment.

Nov 2, 2014 | 10:54 AM

Spartan7

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Quote:

Originally Posted by 1batt4u

I believe the 12v switched works along with the crank, meaning the radio shuts off while cranking, I need constant 12v while cranking, not to shut off.

Then take it off the interior fuse block like I already mentioned. It already has battery and ignition voltage spade connections for doing exactly what you're trying to do.

Nov 2, 2014 | 09:18 PM

1batt4u

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Quote:

Originally Posted by Spartan7

Then take it off the interior fuse block like I already mentioned. It already has battery and ignition voltage spade connections for doing exactly what you're trying to do.

How do I do that? What wires do I look for? Wires going into the side fuse box? Any specific colors or anything?

Thank you again!

Nov 3, 2014 | 04:35 PM

99Bluz28

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From: C. V., Kalifornia

Crimp a blade connector on to your power wire (fuse it) and insert it into the IGN port which right below the 10A fuse for the Gauges. This is where I got power for my wide band reader. I'm not 100% sure but it might connect inline with the gauge fuse.

http://i523.photobucket.com/albums/w...psd8984dda.jpg
http://i523.photobucket.com/albums/w...ps3988f4e7.jpg

Last edited by 99Bluz28; Nov 3, 2014 at 05:19 PM.