Defi Oil Temperature Gauge Wiring

This is for future reference. The wiring is for a 2006 Nissan 350Z and the gauge has been connected to the unified meter and air conditioner amplifier (UM AC amp) located underneath the stereo head unit.

The gauge has 4 wires to be connected:

Orange - To 12V wire when ignition on
Red - To 12V battery wire
White - To 12V wire when small lamp (parkers) on
Black - To ground or negative battery terminal

The UM AC amp has 3 harnesses on the back. The following image shows the pin layout and the wires the gauge is connected to.

Orange gauge wire >>> Wire 46 (Blue/White)
Red gauge wire >>> Wire 21 (Red/White)
Black gauge wire >>> Wire 29 (Black)
The white gauge wire is not currently connected.

Further Oil Cooler Testing

To get some oil temperature readings without the aid of the oil cooler, I covered the cooler core with a piece of cardboard. This is not as accurate as getting readings without the cooler installed at all, but it provides a general idea of before and after temperatures.

Looks like the cooler is doing its job.

Defi Oil Temperature Gauge Installation

With the help of Kam80, this was installed. I cannot stress enough how immensely grateful I am for his help. The installation was stressful for a noob like me as the uncertainty of whether it would work got to me, but Kam's stoic resolve pulled me through.

The temperature sensor is fixed to the oil cooler sandwich plate. Wiring for the gauge is attached to the aircon control harness. Today, I tidied up the wiring inside the cabin - got a couple of 3M Command wire holders and matte blacked them.

See here for the wiring instructions:
http://zkthlz.blogspot.com/2009/12/defi-oil-temperature-gauge-wiring.html

Results so far with oil cooler
Air temperature: 25º C or below
Stop/start on roads 80kph or less: 79-82º C
Freeway: ~75º C

Air temperature: 25-30º C
Stop/start on roads 80kph or less: ~85º C
Freeway: ~80º C

The next step is to test with the oil cooler core covered on the street and then some on-track temperature readings.

Trust/Greddy Oil Cooler Installation

With the impending hot weather and upcoming December track day, I thought I would get an oil cooler. So last week, this arrived:

The sandwich plate contains a thermostat which I believe opens between 71 and 85 degrees Celsius +/- 2 degrees.

With the help of Kam80 and c2888, installation was fairly simple:

1. Take the front bumper off.
2. Mount the cooler core in place.
3. Fit the oil filter sandwich plate.
4. Connect and tighten hoses.

One small hiccup - As my Japanese literacy is non-existent, I didn't see that I was required to use an oil filter for a 1JZ/2JZ. As a result, my OEM filter did not screw on as the sandwich plate thread pattern was different. Luckily, c2888 had a spare Corolla filter that fit - that will do for now.

Big thanks must go to Kam providing a heap of help and taking photos during this stinking hot installation, and Dan for his technical know-how.