I have a NOS VDO 60mm oil pressure 0-10 Bar gauge with silver dot, I was taking the GT fuel gauge as inspiration, it is not a perfect match as the face is deeper in the body when compared to the SAAB 95/96 gauge but that could be rectified ( I bought a SAAB temp gauge before I found the NOS oil pressure gauge) .
I contacted the technical department at VDO about the sender units and they confirmed all 0 – 10 Bar sender units are 10 – 180 ohms, this means I can buy a new VDO unit and If I want to have the 911 oil temp / pressure gauge in the future I can keep the same sender unit. At the moment I want to keep the gauges in the dash original.
What I would like to know is what adaptors are required to install it and what threads they are.
Looking at the Porsche parts manual for a 1970 911 there are two positions that the sender can be. Is there a preference to the position?

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I also have next to the temperature switch two extra wires, what are these used for.

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IIRC here's how it goes.

59 = oil pressure
65 = oil temp
72 = idiot light/low oil

The other wires you ask about are for the decelerator solenoid. Attaches to carb cross bar
You can just see it in your pic.

If your engine has pressure fed tensioners then you should have the union block installed where the pressure sender would go at the front of the engine. Its on the opposite side of the distributor.

If the engine has stock tensioners then you can update the rear pressure sender to a dual pole style with both the idiot light and pressure sender in one unit. Porsche has a part number for a dual pole sender.

The wires in your photo were used for an emissions unit that was removed early in the cars life. The dealers usually cut off the wires so they we no longer seen.

You'll need to run a circuit for the pressure switch from the engine to the front for the gauge, since no stock 6 had these.

I've added this circuit to several factory main harnesses and engine harnesses but its a lot of work to run them inside the original harness; I only do it during a restoration when they're out of the car.

Most people use an external wire(s).
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There is an extra green wire in the stock 914 6 harness that goes from the
engine relay board to the instrument panel.
Use this wire to avoid installing an 'add on' from rear to front.
You will have to add a lead from the sender to the relay board and another
from the back of the instrument area to wherever you place the gauge
The bright green wire from sender to relay panel is added.
My current instrument layout is pictured.
I too want to add a GT type fuel gauge and then install a 911 left gauge.
Rory

Thanks for your replies,
It's good to know, I do not need to worry about the two wires for the decelerator solenoid.
I am not sure if I have pressure fed tensioners, I will have to look at the weekend as the car is not at my house.
Replacing the low pressure warning sensor with a two pole sender unit and adding the extra green wire to the relay board is the easiest option.

These are the gauges I bought off Ebay. When I found the oil pressure gauge I thought it would be an easy task to change the bezel to a black one
but when it arrived I compared it with the SAAB gauge and noticed the face is set back further. It will need to be cut down to get the correct spacing.

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To your question at the top of the thread: "What I would like to know is what adaptors are required to install it and what threads they are"


I added a VDO sender to work with a 10bar VDO scale gauge (combo oil temp/press); on my engine (911T 2.2). It was a case of replacing the pressure switch on the breather plate with the adaptor (items 61and 63 in your diagram). I sourced the adaptor and sender from Hollywood Speedometer here in CA. Don't recall pricing but the adaptor was not expensive.

As others have pointed out, you need to get creative with wiring to get the sender run back to the gauge in the cabin.

- Tony

PS. Nice pressure gauge BTW

For the two pole sensor (pressure and low pressure switch) with the large thread base (993 sender in post 3) what is the part number for the adaptor that will tread into the back of the block and accept the larger thread sender?

thanks,

john