Converting standard "T" oil temp/oil lamp Gauge to "S" model combo gauge

[Jayboundless]

I have a 1969 T with a base model oil temp needle/low oil pressure light (photo 1) and want to change it to the combination "S" gauge with shows temp and actual oil pressure (photo 2). Has anyone done this conversion? and what is involved? I would imagine all of the wires are there. Any help is greatly appreciated.

Current gauge front and back:






Desired gauge front and back:

[LM3929]

real easy. but you need the matching senders as well

Lorne m.

[Jayboundless]

Well that sounds great, but are there any instructions in another post I haven't found? Is the temp sender the same?


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[LM3929]

Yes there is I think in the tech section.

Lorne M.

[Flat6pac]

The temp sensor will do the job. You'll need a 0-10 pressure sender to replace the on off switch on the top front right by the thermostat. Be sure you get the one with fine threads.
Bruce

[Jayboundless]

Originally Posted by LM3929

Yes there is I think in the tech section.

Lorne M.

Doh! I didn't think to look there! 3 de-merits for me.

Thanks!

[LM3929]

No at least 4 demerits and 6 hail Mary's

I would have looked for it I haven't figured out how to do that fancy short link yet

Lorne M.

[Jayboundless]

Alright Lorne, You were partially right in steering me to the tech article. However, the article does not address my particular situation. My current gauge only has a warning light at the bottom of the gauge the goes on when the pressure is too low. Plus it has two other small round lights, that I'm not sure what they do. I don't have an owners manual but maybe there's someone out there that can indicate their purpose?

So if I switch to the desired "S" gauge, I'm not sure what wiring changes are needed (or maybe the existing wires on the old gauge just plug in somewhere?). I just have to imagine the Porsche wouldn't have a completely different wiring harness for this factory available option. The wiring has to work somehow (I hope). I'm also curious what the lights on the "S" gauge indicate. What are the lights that have the "B" and "G" in circles? What is the green "oil" light for?

C'mon folks! This is like a puzzle...it will be fun!

[70basket]

On your original gauge the green light on the right (top in the photo) is oil pressure and the red one the left is charge or generator and the large one on the bottom is brake warning/parking. The combo gauge is top to bottom is brake, oil pressure warning and charge/generator you can move the bulbs out of the old gauge to the combo gauge. There is a dual pole sending unit that you could use to replace the existing sender which will give you a input to the warning light and pressure guage

[Jayboundless]

Ok, this is starting to make sense. Don, do you have a part number for the dual pole sending unit (or anyone)? Can't seem to find it from our host.

Thanks in advance!

[Jayboundless]

Originally Posted by Jayboundless

Ok, this is starting to make sense. Don, do you have a part number for the dual pole sending unit (or anyone)? Can't seem to find it from our host.

Thanks in advance!

Anyone know the part number Don is referring to regarding dual pole oil pressure sender?

[70basket]

Search part number VDO-360025 on our host. I am not positive but I think it should work for your project the thread pitch looks right. Let me know how it goes I am looking to do the same thing some time soon.

[boilersrule]

I have an interest in a very similar project. I have a 68 911 with a 71 engine. Wired to the gage in the post, the temperature reads backwards, ie it starts to the right and goes to the left as the engine heat up. I assume this is a mismatch between the sensor and gauge. My question has been how to identify the correct combination of sensor and gauge for the switch.

[70basket]

Boilersrule

Assuming the wires are correct as in the green wire from engine bay is attached to the g lug on the back the gauge. Then I suspect the sender, it is a variable resistor that if it goes straight to ground will cause a full sweep.