Digi dash fuel sender

-between the single poly mount, 165 single side skirt, and the digi fuel sender.....i think we need a poll on who's gonna be up the longest.

:lachtot

-sry guys i had to.

 

hey i tried out my analog fuel sender with the A14/A19/A20 on the digi dash pins and all combinations did not work. i think the analog one is a straight voltage difference sender, while the digital one is a pulse type. i was shorting out two of the wires from the digi dash and if you just touch the wires a millisecond, it will show as empty fuel, if you hold it together for about half a second it will be full fuel, and everything in between.

i have no idea how this helps, but i hope it does

 

Well for the Analog guage the sender is just a variable resistor
Empty is 4 ohms
Full is 110 ohms





So if we can find the test for the digital sender then it may be possible to create
a conversion circuit

 

Your taking a big chance of frying the circuit board by doing that. The wire from your analog
fuel sender is at worst a very good ground and at best a poor ground. As you can see
in the following diagram wire C7 yellow with a red stripe goes through a variable resistor
to ground so if your gas tank is almost empty wire C7 is a very good ground luckilly their
is at least 4 ohms resistance so that may have saved your display but still almost all of the
voltage would have gotten through. If your gas tank was full then it would have been alot
better because the resistance would have been much higher and alot less of the voltage
would have gotten through. You would probably not want to take a piece of electrical wire
and connect it to the positive and negative terminals of your battery but that is basically
what you did with your test. If you do want to take a piece of electrical wire and connect
it to the positive and negative terminals of your battery then you should probably sell the
digital cluster before it starts to smoke. It is highly likely that one of the 3 wires A14/A19/A20
is a 12 volt supply so touching it to C7 is not a good thing. It is also not a good thing to be
touching the 3 wires A14/A19/A20 to each other.

I highly doubt it. The following diagram definetly shows a variable resistor or a tapped
resistor. It is definetly the symbol for a variable resistor, not 1 that toyota has included
in their Glossary of Symbols but it is a valid symbol for a variable resistor in the electrical
world

 

15A Gauge Fuse, any of the 12v supplied to anything you plug in through A14/19/20 is run through the 15A fuse, even if you short A14/19/20 to each other, the 12v is still fused, while the ground is the only thing that's directly to the battery.

 

I need a fuel digi dash fuel sender aswell has anybody tried a fuel sender off the supra of the same year?

 

That actually does help. Which wires do you short to get the fuel reading?

That would be correct for the analog dash, but I'm guessing it's something completely different for the digi dash.

I'm going to take a guess and say that either the digi dash polls the sender every x milliseconds or the sender is constantly pulsing the fuel level to the dash.

The signals can be converted quite easily using a $4 microcontroller. Are the A14/19/20 pins just for the fuel sender? Do any connect straight to ground or 12v?

 

i honestly don't remember. i've put off the digi dash project for a long time now since i was dealing with HG issues with my old car...i preferred the centre placed temp gauge and the oil pressure gauge doesn't hurt.

i actually got the damn thing to work. it's just figuring out which pin was which.

 

just run an anolog guage lol

 

I was under the impression the big black box sitting on top of the digital sender was housing some sort of conversion circuit?

EDIT: Just noticed the sender on your tank in your thread has the black box too, unless you have the digi dash?

The mystery continues!

 

can it be ordered new?

 

how would someone go about opening up that black plastic thing above the sender? everyone's got the same looking bit on all senders

 

cut around the edge of it with a razor knife, then pop it off.

 

I've got one here. $250 NZD (€159) + shipping and comes with a free RHD digital dash complete with plugs