1996 GTX arduino to replace Infocenter

[hrifaii]

Hi
Several years ago I bought a used 1996 GTX , it ran OK for the low price I payed. The speedometer and infocenter display didn't work. The speed wheel was missing and I thought the display needed A UV film, but when I disassembled it I found a big part of the board inside burnt. I decided to replace it with an LCD and arduino mega to display the info. My concern right now is the fuel sender unit, I understand it contains the pump and the float sensor but only two wires are connected to it.

What I did so far is:
Programmed the arduino to read and display both temperatures, fuel level, oil level and the compass on the LCD screen
I added a gps receiver and programmed it to display speed instead of the speed wheel
Didn't connect to PWC yet

1) I need to know if the pump runs all the time or gets an ON/OFF signal from the control ?
2) I need to know what kind of signal is fed to the speed gauge (PU-YL wire) so I can send the speed value from the arduino to the gauge

Please advice
Thanks
p.s where I live spare parts are either not easily available or extremely expensive

 

[Ankeneyou]

There is no fuel pump in the fuel baffle, it's only the fuel level sensor.

The fuel pump is on the carbs and is activated by the pulse from the crank case.

 

[hrifaii]

There is no fuel pump in the fuel baffle, it's only the fuel level sensor.

The fuel pump is on the carbs and is activated by the pulse from the crank case.

It makes more sense now, Thank you

 

[soccerdad]

You should look up some information on the fuel baffle. It has a series of magnetic reed switches in it. Each one has a resistor on it. As the float goes up and down, it switches the sensors and the resistance changes. That is what you will have to use as your signal to convert. Cool project. Post back when done.

 

[jjsinaz]

Very nice. Kudos to you for thinking outside the box. Keep us posted on your progress if you don't mind.

 

[hrifaii]

You should look up some information on the fuel baffle. It has a series of magnetic reed switches in it. Each one has a resistor on it. As the float goes up and down, it switches the sensors and the resistance changes. That is what you will have to use as your signal to convert. Cool project. Post back when done.

This is what I figured out so far concerning the fuel sensor

 

[hrifaii]

You should look up some information on the fuel baffle. It has a series of magnetic reed switches in it. Each one has a resistor on it. As the float goes up and down, it switches the sensors and the resistance changes. That is what you will have to use as your signal to convert. Cool project. Post back when done.

This is what I figured out so far concerning the fuel sensor
Thank you
View attachment 39721

 

[hrifaii]

Sure I don't mind, but I work slow so don't get bored

 

[hrifaii]

Does anyone know the voltage entering the gauge cluster through (PU-BK) socket from the electronic module MH-146 ? Is it 12v or 5v ??

 

[Kwik_uk]

Very interested to see the progress with this. I don't think my GTI supports the infogauge or I'd follow suit.

Post lots and pictures, and when you're ready dump the code so others can have a play too

 

[hrifaii]

Update

 

[hrifaii]

Update

To run the speed gauge, I found (by try and error) that wire PU-YL needs to be pulled down with a pulse ranging from 30Hz to 365 Hz to cover the whole range of the speeds, I am preparing a schematic and will post as soon as it is ready

 

[soccerdad]

Cool. Great progress and a fun project! Are you going to package it in the old info center housing?

 

[hrifaii]

Cool. Great progress and a fun project! Are you going to package it in the old info center housing?

Yes, this is the plan, hopefully will be done this weekend