ConSynX

iTrader: (1)

so did you do this last nite, and get it to work?

VJ RC51

Ran out of time to plug it up, ill do it sunday. Im leaving at 3pm here to spend the weekend with the GF.

2.5tsoarer

iTrader: (3)

I did the temp thing and didnt work, pegged hot

Dew23

iTrader: (1)

kNOW this works did a car tonight for the tach and temp on a sc400 swap.

RSTSpeed

iTrader: (4)

Awesome work! But I must chime in... MORE PICS PLEASE! :-D

kaosman

This doesn't work, at least on a '95 SC300. Middle plug for instrument cluster has a white wire with a series of gray dashes on it. Then you've got two "brown with gray dash" wires, the difference between the two is one has two dashes in sequence, the other has just one. Bridging the white with gray to either of these results in nothing.

As for the resistor, in the location you specified my cluster has three blueish gray resistors...R130, R129, and R128. I didn't try using a jumper wire on any of these because of the visible difference between the cluster shown and my own. Where there is a visible inductor on the cluster shown, my cluster doesn't have one and I've got a power transistor where the pictured cluster does not.

Considering the differences in the 1JZ & US Spec 2JZ pinouts, I'm going to make a guess and say that the 1JZ tach pin is in the wrong location on the orange body connector, in regards to what the US 2JZ dash harness needs. I'm gonna trace out the stock 2JZ-GE harness and find where the tach wire ends up in the orange connector, versus where the tach wire is on the 1JZ orange connector. This may lead no where but it's better than chasing the wrong wires behind the dash.

O. L. T.

iTrader: (17)

Since the plugs for the SC3 and SC4 are the same, you can have a look at this to see what it is that you are actually doing.

https://www.clublexus.com/gallery/sh...8/ppuser/13879

double click for high res.

kaosman

THANK YOU! I've been searching for a cluster wiring diagram for a while now...you are the man!

EDIT: Interesting...the white wire mentioned above looks like one of the clock wires (for the clock button) and brown is just a ground. Something's not adding up here...

nasc300

So did you get it done

VJ RC51

ill post pics of my modded cluster by thursday sometime. You dont actually mod the wires, you do it on the circuit board behind the plug. I never got in depth on whats actually done and no one will spill the beans, but from my guesses are... your just giving the tach a power source to work.

ConSynX

iTrader: (1)

for the 93 sc300 is seems the tach runs solely off the middle connector piece that is upper left most, and over(right) one on the plug, or upper right most, and over(left) one on the gauges.

i haven't opened mine up yet because i'm lazy. . .
basically just gonna try following the wires and making sure it goes to the ignitor.

kaosman

Well looks like you're right...I got inspired by the diagrams that OLT posted up and tested the tach wire (pin 9 of the middle connector, black wire) and this wire has continuity with the tach plug in the diagnostic connector, and the ignitor. So the issue isn't with the signal to the tach. I took it a step further and checked the two brown wires (grounds according to the diagrams) and one was grounded, the other was not. I grounded both (testing for voltage across first) and it didn't make a difference. I'm gonna look at the diagrams again and see where the tach gets power, that's probably why its not coming on.

RSTSpeed

iTrader: (4)

2 questions:

What is the reason for the tach and temp not working correctly, different wires on the 1jz harness?

And this seems to be a LOT of trouble... why not buy the MSD tach adapter?

O. L. T.

iTrader: (17)

Yep, I checked also and it does say black and it does go to the ignitor as suggested, the diagrams are correct as they should be

The other one that did not have ground may only have ground at a certain point. (key on , or after warm up, etc......)

kaosman

My thought was maybe the pin was different between the 1JZ and 2JZ in regards to the orange body plug, but I was wrong there. Its getting late and I'm not gonna take the cluster out again tonight, but I don't remember there being multiple yellow wires for powering the gauges individually...I'm guessing they share the power source inside the cluster. What do you think? One of the brown wires had continuity with the chassis, but I didn't check to see if the ignitor ground had the same...something to think about.