12V wire when ignition on for gauge

[jim97gst]

What's a good wire to tap into for 12v when ignition on for a gauge installation in a 2G? The gauge is going in the A pillar.

 

[Livid]

Use your ciggarette lighter. Just don't overload it with tons of gauges, but a couple won't hurt.

 

[VelocitàPaola]

As in a 12V supply that remains high through ignition? We had a thread about this before and couldn't come to a decent conclusion.

http://www.dsmtuners.com/forums/showthread.php?t=208447

I suggest using a multimeter and testing several sources before making any permanent connections. I'm pretty sure the cigarette lighter cuts off through ignition, much like the stereo.

 

[jim97gst]

As in a 12V supply that remains high through ignition?

I don't completely understand what you mean by that. It's an EGT and I have 4 wires:

12V constant
negative
powers on with lights
powers on with ignition

I already have a mechanical boost gauge that lights up with the lights on, so I'll just use that same source. I will use a multimeter for the ignition wire, I just thought I'd see what other people are using to give me a starting point.

 

[VelocitàPaola]

Some of the self-calibrating gauges Autometer came out with require a 12V power source that does not cut out during ignition. It turns out, many 12V power supplies drop during ignition (which is why your radio doesn't play anything when the starter is engaged).

At first you said "12v when ignition on." I wasn't sure if you had this type of gauge or not, but once you clarified, it doesn't sound like you do.

 

[VelocitàPaola]

The last time I saw all of those wires in one place was when I put in a new head unit. If you have an aftermarket head unit and wire harness, you could tap into that without any adverse effects.

If you do have an aftermarket harness, the yellow wire is the constant, the red wire is the 12V on ignition, the orange (looks pink) w/ white stripes wire is for illumination, and the black is ground.

If that's not an option for you, check here at VFAQ to find other wires that will do the same function.

http://www.vfaq.com/mods/wiring-gen2wir.html

 

[polonez]

the stereo has a constant power which is yellow normally (on aftermarket harness) and the red is the trigger. This is how your CD player remembers everything(station memory) plus the constant is able to take alot more current.

 

[jim97gst]

Thanks fellas. I got the gauge in this afternoon and everything is working fine. I used the stereo for the constant 12V (red wire on the factory unit), the cigarette lighter for the ignition wire, and the cigarette lighter light bulb for the one to power on with the light.

The cigarette lighter does indeed cut out during cranking. My gauge does a full sweep when it powers up. It does it twice. Once when I first turn the key, and again after I start the car.