Digital Dash Info

What we need to do is find out what the testing procedure is for the digital sender unit.
We know that the analog sender produces a resistance Empty is 4 ohms Full is 110 ohms.




We need to find the above page from an 86-87 manual and hope that it has a test for the
digital sender unit.


If we look at the diagram for the digital guage heres my best guess.


A14 is going to be the signal that is read by the guage and based on some assumptions I'm going
to make will be a voltage from 0-12 volts

A20 & A19 are going to be 12 volts and ground. This is where I make my assumptions. Its a pretty
safe guess since the overall car runs on 12 volts but in the digital world 3.3 and 5 volts are also
popular numbers and unlike the Analog sender which is grounded to the chassis the digital sender
is isolated to the digital displays circuit board so A20 & A19 could just as easilly be 3.3 volts and
ground or could be 12 & 7 volts or 5 volts and ground their are alot of possibilities.

If you want to do a test
Send 12 volts to A2 & A13
Ground A9 & A11

Use a voltage meter and measure A19 & A20

 

One problem that the digital guage clusters have is that they are pretty much impossible
to read when the sun is shining on them. I thought since mine was converted and didn't
have the proper dimmer switch that was the problem but I have heard from people that
had it as the original factory option that they can't read theirs in dirrect sunlight either.

So I went searching for some brighter lights. This is the stock incandecent lightbulb


and this is what I found to replace it with wow.... better use sunglasses with these


the old and the new, the new is a 12 led T10 bulb


originally the bulb did come as a T10 base but its to tall to fit in the guage cluster so I thought
oh crap now I have some extra bulbs where can I use them now


but upon closer inspection the leds are not glued into the T10 socket all thats holding them
in place is a couple of bent wires


so I pulled out the leds


bent the 2 leads over and stuck the whole thing into one of the digital clusters T10 bulb holders


then I wraped each of the leds wires under & around the bulb holders electrical contacts


and then tucked the rest of the wire out of the way


and the result.....as a bonus I got rid of that god aweful puky green color :barf Toyota sticks in all their vehicles
All I did was change the bulbs so I don't have any explanation for the color change but me like :drool5 .


And even in direct sunlight I can easilly read the numbers, unfortunately that puky green is starting
to creep back in but thats life


found out its the digital cluster wiring thats fucking my oil pressure guage so I'll be cutting a wire
somewhere today


Yay a nice blury picture but the Digital Clusters RPM's are way off. At 120kph I should be doing
about 3000 rpm according to my analog cluster. The digital cluster says I'm idling at around 1050rpm
and with the analog cluster I had it set at around 700rpm.

 

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The dash harness comes up to the left of the cluster behind the drivers side window vent
and theres a bit of space there so I try and stuff as much of the extra wiring as posible in
there. I have it set up with the 3 digital cluster plugs and the 3 analog cluster plugs so I
can swap analog/digital anytime I want but it does eat up alot of space

 

The 3 plugs with green tape are for an analog cluster and the 3 uncovered plugs are for the digital cluster