Looking for 12v switched power source at rear of 308 QV

I need a 12v switched power source at rear of 308 QV. Can anyone suggest a good wire to tap into?

I am (finally) installing the oil pressure gauge modernization kit that TacElf and AKimmel built and sold in 2017.

Is the pin marked "12v" pin (right center) on the below diagram of the diagnostic port a suitable source? I worry that the 12v supply might be to the coils and might be affected by the cyclic operation of the coils.

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When Rifledriver did this conversion, he tapped into the switched 12v supply going to the digiplex boxes on his 328 but wasn't sure if the wiring was the same for a 308. Frankly, I am nervous (more at "terrified") with disturbing the wires going to the digiplex boxes no matter what.

 

In my car its a yellow wire and yes it went to the digiplexes...so it is already split. Not sure it there is another option but that is the one I use for the new ECU and such that I mounted in the trunk.

 

I have cut and spliced into the Digiplex harness.

I have survived the trauma.

 

Have you got an oil pressure reading again?

I switched mine over to a modern pressure transducer too, but I have the ecu to read it and relay the correct signal to the gauge....about the same idea I guess and it seems to work very well.

 

Modernizing the oil pressure gauge is part of a bunch of stuff I am doing to the car, so probably won't be able to calibrate the gauge and run the car for a while (2 weeks?).

I am using a stand-alone kit which maps a modern piezoelectric sensor to the existing gauge. I bought it a few years ago and am only now finally installing it. ... and while I have the cluster out, I may as well upgrade the instrument lights to LED, and ... well, while the car is out of service, I may as well send the seats out to get redyed too.

If you are interested, here are the threads that describe the stand-alone system. It's pretty cool, actually. FChat geniuses.
308/328 Oil Pressure Conversion unit
Modern oil pressure sensor kit for 3x8, Mondial, etc.

 

That's a neat setup. I'm using a nearly identical sensor and did a very similar calibration. It seems to work very well ....its kind of nice having the gauge reading the pressure.