Interesting question

[datsunboy]

Hi guys, I have an interesting question for you all.....

I have spent ages looking on the net for a wiring diagram for a L20ET, but cannot find one anywhere.

All I really need to know, is the wiring for the optical distributor. It has 4 wires coming out.....Black(1), Green(2), Red(3) and Black/White(4).....these are numbered on the round plug.

I would be assuming that the Black/White is 12V+, the Black is ground.....and the other 2 would be the 1deg and 60deg signal wires.
but which ones?.....and how would I test the signal wires? (without an oscilloscope) are they meant to give out a voltage? or a 4-10ma type signal or what?

What do other Nissan CAS signal wires do?

Basically, I am trying to determine weather I can use this optical distributor as a CAS for a later model ECU? (the optical disc inside looks pretty much the same as RB/CA style ones, and has 1deg slits, aswell as 60deg slits)

I have already fitted a different disc into it, out of a proper CAS, and trying to check the output....hoping that I dont have to swap the actual brains of the CAS into the distributor body aswell, but it doesnt look to hard if I did have to

[Bernardd]

If you have the 12 feed figured out the rest is easy. Connect the positive of the volt meter to one of the cas outputs in question and the other end of the meter to ground. With the 12vdc connected slowly rotate the cas, you'll see the voltage go up to 5vdc everytime a window or slit in the cas opens to the led in the cas. 6 times per revolution for cyl position with be the inner windows while the outer slits will be very quick to open and close.

[datsunboy]

I dont have the 12v feed figured out 100%.....as I said, I was only assuming that the Black/White wire would be the 12V, as it often was in nissan wiring colors.
Thats doesnt mean that it actually is tho.....there is a red one aswell?

[Matt]

cant remember if its output 12v or not from the other wires

usually black/white is 12V but that would be only taking a guess without pulling all to bits

if you do figure out the main volt/gnd then slowly turning and monitoring output of other two should give away if 1 deg or 60/90 deg

[datsunboy]

so we can't be sure of their voltage on the outputs?

I need to know if I can use the L20ET signal generator and optical pickup, with a CA18 disc, and connected to a CA18 ECU.

I realise the L20ET is a 6cyl, and CA18 a 4cyl.....but that shouldnt matter if the disc's are swapped over?
also the L20ET has all of its 60deg slits the same size....but the CA18 all of the 90deg slits are different size.
But the signal generator should just produce a shorter or longer circuit? depending on what size slit there is....and wont be hard coded/wired in the circuitry?

is this something that really is best left to test on an oscilloscope?