water temp gauge pins and sensor

[baihui]

Hi,

can anybody tell me and show me where the regular water sensor is with image and wires colors. I need also image of where do they exactly go in the body (pic would be great).
I am also wondering what pins these wires are using at the back of the dashboard.

Please help !

[Monkeymagic]

I assume you are talking about the mfts on the water rail. Do a quick Google search I seem to recall sjm Auto tecknik doing a write up

[UrS4boy]

I assume you are talking about the mfts on the water rail. Do a quick Google search I seem to recall sjm Auto tecknik doing a write up

IF it is the F76 MFTS, personally, I think my write-up has more detail:

http://forums.quattroworld.com/s4s6/msgs/22584.phtml

[newsh]

What's your symptoms Baihui?

[baihui]

What's your symptoms Baihui?

well after the engine swap with 1.8 turbo, somehow these wires got lost and now the water temp gauge is not connected to anything.
I have brand new temp sensors but I was not able to find any wire diagrams for the dash hence I do not know the wires (pins) for the sensor.

My goal is simple, get new wires (or use the existing if I can find them) and connect them to the sensor.

What starts to worry me is that the new sensor has only 1 pin and apparently works with one cable where the links above are showing sensor with 3 pins.

That is a bit confusing. I will try however to find the brown yellow wire and connect it. I think this is the one I need ?

http://forums.quattroworld.com/s4s6/msgs/22584.phtml

I can share photos if you wish

[Monkeymagic]

I'm a bit lost here. However 1.8t engine either use a two pin grey sensor ( rare) or a 4 pin green sensor most common.

[baihui]

I'm a bit lost here. However 1.8t engine either use a two pin grey sensor ( rare) or a 4 pin green sensor most common.

Well perhaps it's my fault for not explaining clearly the issue.

Let's take what we have.
1. I have default Audi 90 Dash that is working with the regular Audi 80/90 sensors.
2. I have 1.8 T A4 engine with installed NEW sensor that has only 1 pin, that is intended for Audi 80/90 and is should work with the dash just fine (the A4 senor has been removed and replaced with one that works with my settings).
3. During the swap, the wires that used to connect the dash and the water temp got lost. They might be still somewhere under the hood or they might've been cut or who knows.

So I am trying to find out the right cable that is used by the dash to read the water temp so that I can connect it to the water temp. sensor I have

Does it makes sense now ?

[Monkeymagic]

Now I get it. I don't know the answer sadly but I'm certain someone will be along with a wiring diagram soon

[baihui]

ok so it seems that no one knows. So I managed to find these diagrams.

http://www.sergeynik.narod.ru/audi/shema/3a.pdf

[S2central.net]

Look at Sheet 7 on this schematic for Audi 80/90 with 2.0 16V engine -

http://www.s2central.net/S2_Schematics/A/A09.PDF

The coolant temperature signal is on track 66 - the blue/brown wire that enters the 80/90 cluster on T26/2 - that is pin 2 of the YELLOW 26-pin connector.

[baihui]

thank you very much.

I will give this one a try very soon

[S2central.net]

Seeing as I have the AEB schematics in front of me... there is a 2-pin water temp sensor on that motor - one pin goes to the ECU - the other goes to the gauge. The gauge signal is again a blue/brown wire which you should find at pin 7 (seven) of the black 10-pin plug on the AEB loom.

Do do that black 10-pin plug (T10m) justice - here is pinout for 1997 but it may vary across the AEB wiring years....

01
02 - green/blue from ECU (rpm signal to tacho)
03 - white/grey from F1 (1.4bar n/o oil pressure switch)
04
05
06 - blue/yellow from F66 (coolant shortage switch in expansion tank)
07 - blue/brown from G2 (coolant temp sensor for gauge)
08
09 - brown/red from G68 (speed sensor in gearbox - 80/90 version may or may not be compatible)
10

[baihui]

Look at Sheet 7 on this schematic for Audi 80/90 with 2.0 16V engine -

http://www.s2central.net/S2_Schematics/A/A09.PDF

The coolant temperature signal is on track 66 - the blue/brown wire that enters the 80/90 cluster on T26/2 - that is pin 2 of the YELLOW 26-pin connector.

So I connected a wire directly from the sensor to the pin (yellow socket, 2nd pin, blue/gray wire),
but the gauge does not move at all.
The arrow stays just below the minimum as it has no power at all.

I did the same for the oil temp gauge and it works just fine.

I was wondering if the whole dash works with different pin setup since it is from ACE engine (2.0 16V 4 cyl)?
I was looking at the original NM schematics (as much as I could understand them) and it looks to me that there are two wires related to the coolant signal:
http://www.s2central.net/S2_Schematics/A/A14.PDF - No.1416 (page 7)

From the schematics:
G 3 - Coolant temperature gauge
T 26 - Connector 26 pin, yellow, dash panel insert
T 26a - Connector 26 pin, blue, dash panel insert

Although I could only see that according to the schematics there is only T26/2 (I suppose /2 states the pin number), there is also T26a/16 from the black socket. Is this also supposed to be in the loop in order for the gauge to work ?

[baihui]

So I connected a wire directly from the sensor to the pin (yellow socket, 2nd pin, blue/gray wire),
but the gauge does not move at all.
The arrow stays just below the minimum as it has no power at all.

I did the same for the oil temp gauge and it works just fine.

I was wondering if the whole dash works with different pin setup since it is from ACE engine (2.0 16V 4 cyl)?
I was looking at the original NM schematics (as much as I could understand them) and it looks to me that there are two wires related to the coolant signal:
http://www.s2central.net/S2_Schematics/A/A14.PDF - No.1416 (page 7)

From the schematics:
G 3 - Coolant temperature gauge
T 26 - Connector 26 pin, yellow, dash panel insert
T 26a - Connector 26 pin, blue, dash panel insert

Although I could only see that according to the schematics there is only T26/2 (I suppose /2 states the pin number), there is also T26a/16 from the black socket. Is this also supposed to be in the loop in order for the gauge to work ?

Update on this one.
So the other day I connected again the water T sensor to the oil T gauge so I can keep track on the temp. As for the water T gauge, I got it connected to the oil T sensor.
So after driving the car for a while the arrow moved to 90 C that means that gauge is actually working properly but I keep thinking that the sensor is not for this gauge hence not moving the arrow properly.

Does anybody knows what sensor for the water T should I use that would work with the dash ?

[baihui]

Update on this one.
So the other day I connected again the water T sensor to the oil T gauge so I can keep track on the temp. As for the water T gauge, I got it connected to the oil T sensor.
So after driving the car for a while the arrow moved to 90 C that means that gauge is actually working properly but I keep thinking that the sensor is not for this gauge hence not moving the arrow properly.

Does anybody knows what sensor for the water T should I use that would work with the dash ?

another reply after quite some time now. Well it seems that temp gauge is indeed connected to the proper wire but the gauge itself is damaged and works whenever it wants. Though when it decides to work shows everything properly.

Thanks for the help.

Still the problem with the oil lamp persist though !