Pricing 240z Rally Clock w/ Fully Functioning Oscillator?

[d3c0y]

Yeah the red wire going to the stud is an earth, just like the green and red on the main harness outside the box. The black wire inside the box is positive and yellow and white are the 'signal' wires.

Gav your units that are now in the post come with wiring guides and pin-outs that explain what everything does to wire our one up to the stock plug.

[monkeyman]

From what I can tell from photos I have seen on the internet, I agree with the wire colours to the oscillator plug pins have on your diagram (though I don’t have an oscillator to verify it). 

 

From the wiring harness I have, the way the oscillator/clock harness wire colours match at the plug/socket are like this (using your pin numbering)

 

Pin   OSC PLUG    CLOCK SKT

1        White             Red/Yellow

2        Green            Red/Green

3        Yellow            Red/White

4        Black              Black

5        Red                Blue

 

But although the harness I have looks original, a new socket was spliced onto it. I have assumed it was done right, but it’s possible it wasn’t.

 

It’s interesting to note that both you and I have the White wire going to the Red/Yellow, and the Yellow wire going to the Red/White. It doesn’t matter at all as these two wires are interchangeable.

 

Where we see things differently is where the black and blue wires from the clock go. The questions marks on your chart suggest you are not 100% sure, and the fact that the harness I have has been spliced means I can’t be 100% sure either. 

 

I think one thing that is certain is that the black on the clock harness is ground, as it connects to the case of the clock. The black wire to the clock and the black wire to the oscillator plug are crimped together at the socket that goes to the car. The other wire from the car is Blue and must be the +12V (or +13.6 as you more accurately have it). 

 

If my wiring harness is spliced correctly, then the Blue from the car (+12V) goes to the Red inside the oscillator, and the Black (GND) goes to the Black inside the oscillator.

 

So the above table looks like this:

 

Pin        OSC PLUG    CLOCK SKT    SIGNAL

1             White            Red/Yellow      Signal A

2             Green           Red/Green      ‘common’

3             Yellow          Red/White        Signal B

4             Black             Black               GND

5             Red               Blue                 +12V

 

This is different to what you have. I’m sticking with this (for now) because it makes no sense to me that they would use Black for 12V and Red for Gnd. The only reason I doubt this is that the Red goes to what looks like a stud on the oscillator case, which would be grounded through the chassis mounts. But if the stud is an insulated bushing passing through the case, then there is no issue (but then why would you not just run the red cable through a hole like the other cables?).

 

Greg, Gav, are you able to confirm the wires going to the oscillator socket/plug at the harness or at the oscillator?

[Captain Obvious]

That red wire is the ground connection? Really? Respectfully submitted and no controversy intended as I've never seen one of these things in my life, but from what I see in the pics, my forensic intuition doesn't like that conclusion. I know you guys must have figured this stuff out as you've got working parts, but I'm thinking maybe I'm missing something.

 

In general, the ground connection goes to lots of places on the PC board. Usually more connections than any other signal, and sometimes will encircle some or all of the outside perimeter of a board. In general, the incoming power passes immediately through a section of circuitry to regulate and condition the power input. Certainly not a sure fire way to tell, but I use that as a litmus test. The black wire passes that litmus test while the red does not. It looks like the red connection goes immediately to a couple components and nowhere else.

 

Also, the negative sides of all the electrolytic capacitors are connected to the black wire.

 

Also, there is a little "+" and "-" circuit printed on the board. The "+" is next to the red, and the "-" is next to the black wire connection, just as I would expect.

 

That little "stud" looks like a feed-thru capacitor to me. Intended to prevent high frequency noise from entering or leaving the inside of the metal clamshell on that wire. Presumably used in this application to prevent high frequency ignition noise from getting in there and messing with the internal oscillator?

 

And lastly... If the case was connected to battery+, then wouldn't this thing dead short out when you bolted it in place? Is the mounting bracket electrically isolated, or is it connected hard to chassis?

 

Like I said, I've never seen one of those and know nothing about it other than what I can glean from the pics, but it just doesn't sound right to me. Is all this stuff reversed Down Under? 

[hr369]

9 hours ago, monkeyman said:

 

I think one thing that is certain is that the black on the clock harness is ground, as it connects to the case of the clock. The black wire to the clock and the black wire to the oscillator plug are crimped together at the socket that goes to the car. The other wire from the car is Blue and must be the +12V (or +13.6 as you more accurately have it). 

 

If my wiring harness is spliced correctly, then the Blue from the car (+12V) goes to the Red inside the oscillator, and the Black (GND) goes to the Black inside the oscillator.

 

So the above table looks like this:

 

Pin        OSC PLUG    CLOCK SKT    SIGNAL

1             White            Red/Yellow      Signal A

2             Green           Red/Green      ‘common’

3             Yellow          Red/White        Signal B

4             Black             Black               GND

5             Red               Blue                 +12V

 

This is different to what you have. I’m sticking with this (for now) because it makes no sense to me that they would use Black for 12V and Red for Gnd. The only reason I doubt this is that the Red goes to what looks like a stud on the oscillator case, which would be grounded through the chassis mounts. But if the stud is an insulated bushing passing through the case, then there is no issue (but then why would you not just run the red cable through a hole like the other cables?).

 

Greg, Gav, are you able to confirm the wires going to the oscillator socket/plug at the harness or at the oscillator?

Eric, I have serveral unmolested harnesses here and they match what you wrote here.

 

Also, this diagram shows how the oscillator is powered. Blue + and black -

 

Since we're getting into harness configuration I might add that there is a later harness for the s30 but the wires are all the same color as the

earlier harness.  Just the plug on the clock side is different.

 

 

Edited September 7, 2016 by hr369

[Gav240z]

2 hours ago, hr369 said:

Since we're getting into harness configuration I might add that there is a later harness for the s30 but the wires are all the same color as the

earlier harness.  Just the plug on the clock side is different.

That's because the 2 knob rally clock was available up until 1974 (S30Z's) in Japan. 1974 is when the dashboard design changed (most export markets refer to this change as 260z dash) but really it's just the 1974 model updates.

As a result the clock housing and wiring loom was changed to suit plug and play into the later dashboard.

Very similar to the 1974 Jeco clocks.

Basically instead of having independent loom for power and the globe, it was placed in 1 single loom plug. The housing also had a strap that runs along the back for mounting into a later dashboard.

I've bought a few of these clocks that have been tampered with, some earlier clocks were modified to suit the later dashboard and some later clocks were modified to suit the earlier dashboard. (1 had a bracket mig welded on! - thankfully the clock was ok - idiots..).

All the ones I've had restored have been to suit the earlier dashboard, mostly because 240z owners are more likely to shell out for these, but also because all my S30Z's are 240z's.

The clocks are literally identical otherwise, the only main difference I know is that there is 2 versions of Oscillator tuning fork (see pics above), but no way to know which you have unless you open the unit and have a look. I'm not going to say which is supposedly better because these statements tend to grow legs and become urban legend before long and have unintended consequences....where people start posting things like "Wanting to buy Rally Clock with Early/Late Tuning Fork) etc.. when in reality it would make little real world difference to them or the clocks operation...

Let me see if I can get Ron to chime in on the wiring details above, I haven't really sat down to look at it yet (haven't receive my aftermarket Oscillators) but definitely don't want to blow anything up by getting polarity wrong. Clock motors are impossible to replace as far as I know...(another urban legend for you).

 

[monkeyman]

Yep, a feedthrough capacitor makes a lot of sense. I’ve never seen one, but this looks like a good place for it. If it is a feedthrough cap then the wires going to it could be the +12V after all, and things start making sense. (Everything the Captain has written makes sense… and no, we aren’t reversed down here, but I think those left-hand drive Zs in the U.S. could be ;-)

 

Greg, the wiring diagram you translated doesn’t look right. The colours you have indicated are reversed to the wiring loom I have. The wire you indicate as being blue (+) connects to the loom socket that has two wires coming from it on the diagram, one to the oscillator and one to the clock (to its case?). The other plug (you have indicated as being black) just goes to the oscillator. 

I have the colour of these two reversed on the loom I have here. The plug with two wires coming from it and connecting to the clock case is black, not blue.

Could you have got the colours reversed in your translation?

 

Gav, where do you store all this info? … must have a big head….;-)

[Captain Obvious]

10 minutes ago, monkeyman said:

we aren’t reversed down here, but I think those left-hand drive Zs in the U.S. could be ;-)

Right of course! (Or is that left?) 

Here's a pic of a random feedthrough cap that I nabbed from ebay. They are commonly available as screw in, or press/solder in. I'm assuming what you have is not threaded. Here's a generic example:

[Captain Obvious]

And forgot to mention... That since the surface area is so small and the gap between the "plates" is relatively large, the end result is that the capacitance of said feedthru's is generally very small. That means they work great for high frequencies, but not so great on lower frequency stuff.

The auction for the caps that I posted above are 1.5 picoFarads

[hr369]

4 hours ago, monkeyman said:

Greg, the wiring diagram you translated doesn’t look right. The colours you have indicated are reversed to the wiring loom I have. The wire you indicate as being blue (+) connects to the loom socket that has two wires coming from it on the diagram, one to the oscillator and one to the clock (to its case?). The other plug (you have indicated as being black) just goes to the oscillator. 

I have the colour of these two reversed on the loom I have here. The plug with two wires coming from it and connecting to the clock case is black, not blue.

Could you have got the colours reversed in your translation?

 

 

Eric, that's a really bad picture but my wife says she can read the kanji. We went over it a 2nd time. Blue- power supply , black-earth

Here is another photo. It doesn't give wire colors. Just says power supply and ground.  Not sure what the "B" and "L" mean. Any ideas?

 

Edited September 8, 2016 by hr369

[hr369]

4 hours ago, Gav240z said:

I've bought a few of these clocks that have been tampered with, some earlier clocks were modified to suit the later dashboard and some later clocks were modified to suit the earlier dashboard. (1 had a bracket mig welded on! - thankfully the clock was ok - idiots..).

The clocks are literally identical otherwise, the only main difference I know is that there is 2 versions of Oscillator tuning fork (see pics above), but no way to know which you have unless you open the unit and have a look. I'm not going to say which is supposedly better because these statements tend to grow legs and become urban legend before long and have unintended consequences....where people start posting things like "Wanting to buy Rally Clock with Early/Late Tuning Fork) etc.. when in reality it would make little real world difference to them or the clocks operation...

Let me see if I can get Ron to chime in on the wiring details above, I haven't really sat down to look at it yet (haven't receive my aftermarket Oscillators) but definitely don't want to blow anything up by getting polarity wrong. Clock motors are impossible to replace as far as I know...(another urban legend for you).

 

I think i read somewhere that Ron was doing these conversions from later to earlier rally clock.  I do know he does a conversion to update the old 240z jeco with a quartz movement.

There is a guy on youtube that put another motor from another car clock in his jeco clock so its possible. Jeco made other rally clocks for other cars too. They're a bit different looking but it's probably a good bet that they used the same motor. 

I believe the synchronous motor should  just spin the wrong way if you reverse polarity to the poles and both oscillators are reverse polarity protected.

 

 

 

 

Edited September 8, 2016 by hr369

[monkeyman]

Blue = power supply, Black = earth. That sounds good. B and L are just the colour codes. 

Greg, If you look at your previous post with your hand-drawn sketch of the plug and wire colours, the drawing from the manual you include in that same post also shows the colours. The letters used in the manual match the letters you uses in your sketch to designate the colours. Only that B is used for Black, and L is used for Blue (as B is already gone).

 

The motor won't go backwards, it can't. It has a 'pawl' to prevent it (remember, you were the one who told me about pawls). I'll put a photo in of the pawl. It is a kind of Spring-loaded arm. When the clock goes the wrong way, the pawl moves until the spring catches and it bounces back in the right direction. I will try to include a video of it working. When power is applied to the clock, there is a 50% chance it will start going in the wrong direction, and that’s when the pawl does its work.

 

Applying power in reverse to our circuit won't do anything. The circuit is protected by a diode, it just won't work until the supply is swapped. I tested this a few times. d3c0y has said his circuit has protection against a reversed supply too. I think either would connect with a dedicated plug (in place of the oscillator box) to the clock harness without trouble. Just making sure the incoming +12V and GND go to the right place on the PCB and don’t need reversing. 

 

Our clock could be installed into an oscillator box with no changes to wiring either. Our oscillator uses +12V as the ‘common’ signal to the clock, and I believe the original oscillator wiring connects the clock ’common’ to the +12V coming from the car (where the Red and the Green wires join at what looks like the feedthrough capacitor at the oscillator). I was unsure of this but the more I read here the more convinced I am that that is how it was done. This matches our oscillator operation. I think d3c0y’s oscillator uses ground as the clock ‘common’. No big deal, but I think the green wire at the oscillator would have to be disconnected from the red wire at the feedthrough capacitor and connected to the ‘common’ pad on the PCB or possibly to the black wire somehow. That’s only if you wanted to install it in an oscillator box. I’m not sure how likely that is.

rally clock pawl.MOV

Edited September 8, 2016 by monkeyman

[hr369]

Eric,  I was speaking theoretically on going backwards. Do you think i would forget the pawl?    

He just has to be careful that he doesn't put the full 12v from the  car into the motor poles. Those motor wires are very thin.

Gav, what are you going to use for a box?  please post pics when you get it running.

 

Edited September 8, 2016 by hr369