Greddy EGT gauge Pin out help

[mastamawk]

Hello All

I have a Greddy EGT gauge (non peak hold) that i got second hand without the power harness I was hoping someone could hook me up with the pin out to wire colors on the 4 pin connector so i can make my own harness. the back of the gauge looks like this.

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if someone could take a look and let me know or post a picture of the harness plugged in it would be much appreciated.

Thanks in advance

 

[4Lurker4]

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and

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via
Help on Greddy SMI and other Greddy gauges. - GT-R Register - Official Nissan Skyline and GTR Owners Club forum

I know this one has both 4 pins connectors, just look at the 4pin, the 3 pin in your case if for the signal from the sensor (this one is for daisy chain)

If it's the SMI unit (the one with the control box) they use the same wiring as the Defi BF/Link in case you want to buy the wire outright.

 

[mastamawk]

Awesome! Thanks dude

Wait is it just the picture or are the wire colors orange, white, black, yellow? The schematic says red, white, black, orange. Is it just me?

 

[4Lurker4]

All the gauges I've ever had orange is ignition, black is ground, white is lights and red is positive 12v. I can only assume your yellow is red in this case (I'm a Defi guy, don't actually own Greddys...well I do, but the SMi ones). That's the best I can do without going out and buying the gauge myself

Best pic of the back connected I could find, but looks like my theory on yellow = red is correct as it's on the end of the connector.

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[mastamawk]

Ok so I have done a little experimenting and found that (looking at the back of the gauge) starting left to right it looks like the pins are lights, ground, 12v, & 12v but I cant tell which 12v is ignition and which is constant power. Unfortunately this doesn'treally match any of the diagrams that I have seen but im not sure if it even matters which one is constantly powered and which one is switched with the ignition.

 

[4Lurker4]

Don't think it matters, I know for Defi's and GReddy SMi the ignition just powers that initial sweep on startup and enables it to read the signal. Our red/orange/white/black wires are on the control unit though, but are connected to the gauges via a link cable. When I test my gauges (BF Defis) I have to have lights, 12V and ignition plugged to the positive and ground to negative to get a sweep and make sure it zeros. Not sure if the GReddy without a brain box has a ceremonial start up sweep. Ignition would be on when the car is turned on anyway, so no harm in having it connected.