New World Datsuns...

Is this all because I said you were really, really close?

Yes, yes it was! Oh, and apparently I do need a speed sensor for the rb, otherwise it does a fuel cut after 6-10 seconds of wot. Sigh. That should be a wrecking yard find hopefully the speed sensor I got with the transmission was broken of course. Just another hundred bucks just another hundred bucks. Good news is Maxima gauge cluster I have has a speedometer that will work with a speed sensor that I can also retrofit in.

Hmm. I have a speed sensor... But I think the wires were cutoff flush. I dont remember seeing in the wiring diagrams of it actually going to the ECU... Of course this is a CA Im talking about... Ill have to look again. Thanks for posting all of this. CA and RB are so similar.

Well apparently the RB20 trans is basically a KA trans with a different bellhousing, so theoretically, any of the speed sensors for 240sx, 96-97 D21 and probably even the early Frontiers with KADEs should work. I'm thinking maybe they even kept it the same sensor for front drive platforms during those years, but I'll have to do some pull and save digging. I'd prefer the cable original drive, but I can retrofit the '97 Maxima gauge to the 910 just like I did the tach. It has 4 connections, I assume power and ground and the two wires for the speed sensor.

Nissan D21 Pickup 1995 - 1997
Nissan D21 Pickup 1996 - 1996
Nissan Frontier 1998 - 1998
Nissan Frontier 1999 - 2001
Nissan Pathfinder 1994 - 1995

So that's the interchange for the speed sensor for a D21. Theoretically it should work. Just swap the gear and see what happens. The wiring specialties harness already has the connector for the speed sensor. It looks like the difference is the other car models have the connector built into the housing instead of the wires coming out with a connector end. I suspect they're going to be the same if not close enough to work. Should be the same 38mm hole. And those speed sensors I should be able to find a hell of a lot easier. In fact, the local parts store has a new one in stock. I'll grab a pull and save unit first for testing. Have to remember what I did with the old broken speedo sensor. It came snapped off on my transmission, courtesy of some dickhead Japanese auto wrecker gorilla.

Looks like the connector may be slightly different, but it's only two wires and or modifying the fins on the plug to fit anyway. The only problem may be the tooth count on the gear. I think the original gear is a round shaft, not the semi-half cut shaft of the speed sensor. Not sure if they'll attach the same way. I do think they were very close on teeth count though.

Son of a bitch. I probably threw away the old broken speed sensor that came with the transmission. Can't find it in the garage or the basement. I suppose I'll grab a couple at PNS and hope to get lucky. I know the current gear count on the trans is correct since it's from the original Maxima unit. I'm not sure those gears remove from the shaft though, I think they're made all one piece. The roll pin gets undone and the whole gear and stem comes out of the housing. Which means I need to count the teeth, then find the gear from one of the other vehicles in pns with the speed sensor I need and make sure it has the same count.

And then the wiring specialties harness has a pair of wires marked "speedo" and a single wire marked "ecu speed in". I assume the two together are for the sensor. But is the speedo in power, or ground? Yeah. Going to go check that wiring diagram again. And I still have to fix the high idle issue. Have I mentioned I really don't like wiring?

Um yea. Nissan used the same transmission behind everything, sans the higher power stuff. RWD CA/KA/SR/VGe all got the same transmission. So S13/14 kids are a good source too.

Yeah, so I get out to pull and save about 40 minutes before they close. Storm moving in. Find a Frontier, wrestle with stubborn bolts, deluge starts raining sideways. Finally get the speed sensor out, dirty, wet, pay for it. 2 buck entry and 4 bucks for the speed sensor. In the car, I think, hmm, this sure seems different. Wasn't that an '03 Frontier? Crap. 6 bucks worth of fail. No, it's not the same. AAAAARRRRRRGGGGGHHHHHH!!!!

My thought now, is why can't I fasten a speed sensor of some sort onto the existing mechanical speedo and make the damn thing work? It would have to be something not immersed in oil. Although it certainly looks like the 240sx speed sensor isn't immersed in oil except for the shaft. I think anyway. Wish I knew if I had thrown away the broken original speed sensor or not. Pretty sure I did since I had the original Maxima sensor installed and I knew it would work.

Here's some interesting reading. And now that I think about it, it's correct. The factory broken off speedo gear was a gear, not a sensor. Apparently the conversion happens somewhere in the dash with a converter box of sorts Nissan made. WTF.

https://www.sau.com.au/forums/topic/449 ... ed-sensor/

So anyway, that explains why I threw out the old speedo gear, it was regular manual as well. So the correct thing is in the transmission. But I'm now thinking about the best way to make it work.

My electrical guy said try to piggy back the ecu speed in wire off the tach wire and see if the signal is close enough to the same to fool the ECU into thinking it has a speed sensor. Makes sense, then I'd still just have the regular manual speedometer which works. I suppose I can hook it all up and see. Part of me wants to put in a speed sensor and adapt the '97 Maxima speedo gauge as well, but it would be much easier to just jump a wire and call it good. Maybe I'll email wiring specialties again for some wonderful help, lol.

Make it all electric. Adapt the Maxima speedo.

Might as well, right?! Lol, it will be easier than having to worry about the speedo cable. The only thing I don't know now, is which gear to use. I assume the old Maxima tire size is probably smaller than the new Maxima tire size, so it should read fast, but the old Maxima gear is smaller probably than the 240sx gear. So fuck, I don't know. Niko has a buddy who has one, should get it Saturday. In the meantime I can screw around with that idle issue and hopefully fix it. I will say the speedo cable is a bitch to get unclipped from the backside of the gauge cluster. And as far as the speedo being off, I'll probably yank the needle and set it on the freeway at a sustained speed while checking gps. Or find a calculator online that I can put gear ratios in to determine speed and figure it out that way. It's a bit more math than I want.

Sweet! So I just had a wild idea. I used to have an NX2000, 91, about the same tech as the RB. So I just googled the instrument cluster, found a pic of the backing. It's the same as the '97 Maxima. Granted, the pathways go to different plugs, but I have a FSM for the NX2000, and I'm sure it identifies where the 4 terminals for the speedo go. And considering it looks identical to the other Maxima, I should have my wires sorted out in no time flat this weekend!

Didn't the Pulsar NX get a CA? That should be real similar to an RB.

Shit yeah! I wonder if it is? Of course, good luck finding a gauge cluster to rob. Hardly see Pulsars anymore, let alone the NX. That's a rare beast.

https://www.ebay.com/itm/1986-NISSAN-PU ... SwMPxereNg

$163 is a lot of gamble. Round gauges in square holes, I was thinking it would fit the same, but oddly, the 910 cluster is shorter. Much more 3x5 card instead of square coaster. Still cool though. I wonder about an R31 Skyline gauge cluster.

https://www.ebay.com/itm/NISSAN-1980s-S ... SwMyBezMP7

DAMMIT! Nope. Here's an R30 gauge cluster. Straight squares, not rectangles. I'll keep going with what I have.

Why Datsuns so complicated?

Okay, so the Maxima speedo will not work. Reason being, the circuit board is too high and will hit the 910 gauge housing. I did, however, find the trip meter can be taken out easily. Annoyingly, the speedo needle is splined and has to be removed to get the push button out. However, if you cut the plate below the opening (which is hidden by the gauge cluster face anyway after it's assembled) you can get the odo out and swap it by itself. Which means I should be able to regain a functioning trip meter without changing the original odometer. So I'm keeping the 910 speedo. I know it works and it's accurate.

The next problem is, how do I make a speed signal so I can have a little box that sends info to the ecu? I'm thinking I can actually cut the '97 Maxima gauge cluster in three sections, making a little box for just the speedo, then either run an external speed sensor (like an ABS sensor on a Subaru) to the box, then to the ecu, thereby giving my factory cable, but satisfying the ecu, OR possibly use another opening in the transmission for a speed sensor. Or make some sort of adapter box like the Dakota Digital speedometer retrofit thing. Trying to think how I would do that. Any ideas are appreciated.

Right now I'm thinking of an electrical box (like household wiring) and running a short section of speedo cable in, to I guess another speedometer gear. Or rather, it would have two female fitting speedo cables in it, in the middle would be an external gear, don't know how yet, then a mounting point for the 240sx speed sensor, which would be turned by the original cable system. It would probably need it's own little gearbox essentially with oil in it to keep the shafts happy. Fuck this seems like a lot of work. Maybe a separate wheel speed external sensor with a trigger wheel off the diff flange or the driveshaft? That might be better.

Anyway, I'm going to eat lunch while thinking. See pictures below.

???
https://www.mnrelectronics.com/250-4160 ... gIsuPD_BwE

https://www.speedhut.com/ecommerce/prod ... -Converter

S13 is in fact a electric sender. Not mechanical. My CA speed sensor is electric.