I decided to install additional gauges to my 323i:
Oil pressure
Oil temperature
Voltmeter
All original VDO, from the old series therefore matching style of E21 interior perfectly.
I made a guide, maybe someone will use it in the future.
In order to make oil pressure and oil temperature gauges working you need proper senders. It is important, the senders are the same brand as the gauge, and of course the same scale and unit (eg VDO pressure sensor, the scale of 0-5, bar).
I got a new oil temp. sender and used oil pressure sender (Audi / VW) which I cleaned up and painted. The temperature sender is the gold one:
Oil pressure sender from Audi / VW has two contacts:
WK - the light on the dash
G – Gauge
I left the original BMW pressure sender and used the Audi sender for the gauge only.
With the senders ready there’s always a question where to install them to the engine. I bought a special adapter for the oil filter where I installed the senders to.
The only thing I did to it was changing the color.
And that how it looks installed to the engine
Next step is preparing wires. Every sender needs one wire to be connected to the gauge (each about 2 meters long).
Also you need wires to connect the gauges to car electrics;
1. One wire for "Ground"
2. One wire for "+" after turning the ignition on
3. One wire for "+" for the gauges lights
As for gauges contacs there are three of them on each gauge:
1. + - where you connect "+" after turning the ignition on
2. G – where you connect wire from the sender
3. - ground
In voltmeter you use only two contacts "+" and "-".
That’s how it looks in the engine compartment.
Red - the wires that go to the senders
Blue - wire to the factory pressure sender
Brown color - ground
That's where I got the ground from for the oil filter adapter.
All the wires in the car waiting for gauges
Black and black-red are the wires from the sender. You connect them to the G contact on the gauge
And now how to connect the gauges to car electrics:
Brown cable need to be connected to cars ground
Next is „+” after ignition is on. You can connect it to the green cable running from the steering column
And last, the „+” for gauges lights. White-blue cable from lights switch is best to connect the gauges lights to it because the lights dimming will also work on gauges.
WARNING! It is crucial you don’t connect „+” to the oil pressure and oil temp. senders . If you do, most likely senders will brake down.
Red arrow: cables to oil pressure and oil temperature sender
Blue arrow: "+" after the ignition is on
Brown arrow: "ground"
But before the gauges can go to the car there are still some modifications required for gauges. I took the gauges apart and painted the needles white and I painted the bulbs using red transparent paint. Now the gauges illumination matches the E21 factory illumination.
The last issue is where to install the gauges.
I decided to do it like BMW E21 tuners which is on top of the dashboard. Althought I didn’t buy one from the shelf gauge cluster. I built one myself using E21 dashboard so now the texture and the color of the gauge cluster match the dashboard perfectly.
I used doublesided tape to install the gauge cluster to the dashboard but before I had to made a cut in the cover so the wires can go through
Here’s how it looks when finished. I’m very happy with the result.
Rgs,
Marcin
