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Hey everyone,

I just bought a voltmeter, but the instructions that came with it are incredibly vague, i think the only actual words it has on it are "Voltmeter" and "OPENING CEREMONY" lol.

So does anyone know how to wire the red and yellow cables to an ignition switch, or fuse? I imagine tapping the fuse box would be easier, but im not sure how to do it?

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A brand name, model and pic of the wiring will help.

I've installed a few of these and they are all different.

Ok, its just a cheap brand, Dragon Gauge. Couldnt tell you what model lol, unless you are talking about my car?

Here is a picture of it:

post-61550-1244298123_thumb.jpg

You can see there it has a yellow and red wire, which i gathered you have to connect to an ignition source, and the black cable which would be the earth?

Okay, the thing that confused me was the lack of mention of a ground wire.

The red goes to IGN, and the black to ground.

I assume with this model of gauge (I haven't come across Dragon Gauge) that the yellow wire performs a small lah-de-dah when you first switch the ignition on. Some will light up and some will make sounds, or a combination of both. If you don't want the "opening ceremony" leave the yellow wire disconnected.

Let me know how you get on.

Okay, the thing that confused me was the lack of mention of a ground wire.

The red goes to IGN, and the black to ground.

I assume with this model of gauge (I haven't come across Dragon Gauge) that the yellow wire performs a small lah-de-dah when you first switch the ignition on. Some will light up and some will make sounds, or a combination of both. If you don't want the "opening ceremony" leave the yellow wire disconnected.

Let me know how you get on.

Lol so thats why it had opening ceremony on the instructions lol.

Im still not sure how to wire the red one though, where is the ignition cable that i am wiring it into, and how do i get to it?

Lol so thats why it had opening ceremony on the instructions lol.

Im still not sure how to wire the red one though, where is the ignition cable that i am wiring it into, and how do i get to it?

Depends on where you site the gauge, but the best place to wire it into is the ignition harness under the steering column knee panel.

If you have a multimeter or volt tester you can find the wire when you switch the ignition on.

You'll obviously need to extend the wiring to reach your desired tap point but there are usually 7 day auto shops open who will have what you need to successfully perform your task.

i would presume the yellow wire to be tapped into the lighting wiring so when lights are on gauge is illuminated

That's what i think too. You could try and hook it up to your parker lights, it should dim the gauges at night cause it might be too bright.

Im not sure about the whole ignition harness.... but ive wired all my extra things to my ecu. This is because ive hooked up a Apexi Rsm previously so i knew where all the wires were down there.

Basically all you need is to find the ign wire. It will most likely be red. You can get this from the ECU or have a look under ur dash. When you find a red wire that may be a ign wire. Cut it and use a volt meter to test if it has power. If it does, wire it in. Then look for a ground wire.. should be black and wire that in. THe last wire: being yellow, look for ur parker wires... im not sure about this one as all my equipment has auto dimming built in... but a bit of trial and error wouldnt hurt.. or someone on here will be able to let u know.

May i ask why u wish to install a voltmeter? Many devices like RSM, SAFC as well as some turbo timers do tell you the Volts... as well as other features.

Edited by br3ndan

I agree the whole Voltmeter thing is a waste of time, if the car doesn't start, you don't have enough volts :thumbsup:

Anyway, all my wiring have been done to the wires behind the ashtray underneath the Stereo, you should have access there to all the +12V, GND and Illumination wiring for the cigarette lighter. Splice the wires and solder is best, but you can buy connectors that simply pierce the wire without the need for cutting.

Ok so how do i get to the ignition harness?

Lol, total noob at this =P

Drop the knee panel under the steering column and it'll be there. It runs down from the center of the steering column, and if you have an immobiliser installed, you'll notice a heap of black wires taped up into this harness.

A word of warning - If you want to start tapping into the ECU harness without knowing exactly what wire does what, you could end up paying for it. Some of the pinouts on the ECU are very sensitive and being a self confessed noob, I wouldn't put any money on you pulling the job off. Another point to consider here is that if you load up too many things on the ECU harness, you could end up frying something or constantly blowing fuses and you'll begin to wonder why. The advice is good as long as you know what you're doing. I've seen some bodgy work in this area due to turbo timers, and even aftermarket cruise controls, just be bloody careful.

Behind the center console is a good spot if you are going to be installing the gauge near there, but the same rule applies with overloading the circuit. Another point with the cigarette lighter circuit is that it initiates on ACC, which means that the gauge will be powered up when you're parked somewhere listening to music or whatever. I once had a member come to me trying to figure out why he was constantly blowing fuses. He had wired his boost controller switch to the OEM radio circuit and it couldn't take the extra power surge. It's just something to keep in mind here. You can wire up to this circuit if you wish, but keep in mind these factors.

As far as the yellow wire is concerned, some gauges are self dimming, some have a smoke background which automatically light on power up, some have a wire to bypass the power up "welcome", and others have a separate light source, or a combination of all of these factors. The only way to find out for certain is to momentarily tap the wire to the +12v once you locate your supply.

Good luck man.

I agree the whole Voltmeter thing is a waste of time, if the car doesn't start, you don't have enough volts :(

Anyway, all my wiring have been done to the wires behind the ashtray underneath the Stereo, you should have access there to all the +12V, GND and Illumination wiring for the cigarette lighter. Splice the wires and solder is best, but you can buy connectors that simply pierce the wire without the need for cutting.

Are you able to tell me what colour the illumination wire is for my future reference? As no doubt ill end up buying something thats not auto dimming.

Also ^^

Agreed on ECU... should of probably said that... When it comes to wiring.. if ur not sure best not to do it. As wiring problems can be a bitch to locate and fix!

Or provide a few beers and call some sau people around :thumbsup:

I agree the whole Voltmeter thing is a waste of time, if the car doesn't start, you don't have enough volts :)

Haha yeh but by then its too late isnt it? Atleast if i am parked listening to music then i can keep an eye on the voltmeter and switch the car on when it gets a bit low

Haha yeh but by then its too late isnt it? Atleast if i am parked listening to music then i can keep an eye on the voltmeter and switch the car on when it gets a bit low

Each to their own man, everybody's opinion is different.

However, even though your voltmeter will show 12V, you may not be able to crank the engine due to lack of amperage. Also if you read what I stated in my previous response to this, I advised that the voltmeter be connected to the IGN, not the ACC. Whichever way you do it is up to you entirely, but don't count on the voltmeter for the reason stated above.

Voltmeters are used primarily if your vehicle is not installed with a charge fault warning lamp to alert you if the charge is insufficient or exceeding the required parameters. The R34 is fitted with this lamp, so in essence what Gts-t VSPEC has stated is correct, but people install them for a certain effect in their cars. Nobody is saying what you are doing is wrong, but more that it's not completely necessary.

Again, each to their own and what you do is your choice.

Later man.

easy to find out what color is what. just get a car battery put black onto neutral and try out the red and yellow. one of them u should get a volt reading and the other should be the light. The Good old Cigarette lighter could be a good tap in point. its got a ground as the black, ignition power , and a light source wire u could tap into to illuminate your gauge .

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