S14 RB25 gauge cluster issue

[NASTY]

So here's the deal guys, I had my harness re-pinned from the guys a psycho performance. It's a Series2 RB25 in an S14. From what I can tell everything is pinned out and wired correctly but I still can not get my tach or speedo to read at all. Anybody here skilled with electronics and wiring that can give me a hand? The car also has a Haltech computer and I can see that it is atleast reading RPM. We have checked and double checked everything that we know and at this point I am stumped. Any info?

[mattleegee]

Neither will work, you need to read up on it

you need a new VSS from a z32 or dakota converterand your tach is for a 4cylinder so you need a 6cylinder one or a

[NASTY]

Maybe you should do a little more research yourself. They WILL work but the tach needs to be calibrated or at most needs resistors to be accurate depending on which one you have, however the tach reads nothing right now. The speedo WILL also read off of the RB25 sensor, RB20 sensor, or KA sensor depending on which transmission you use and is also reading nothing right now. There are quite a few swapped cars using the stock cluster with the stock RB sensors. Before you try and send people in the wrong direction do a little more research. I've read and researched just about everything out there.

[mattleegee]

Allright guy your first post made it seem like you had no idea why they where not working you dont have to be an a$$

Also exactly you can send your tach in for $80 and get it calibrated right but it wont work right by itself, you STILL need to do something, i was typeing it out but forgot to add that in there as an option; sorry

Really? I didnt know the speedo worked with a RB25 sensor, please let me know it will save me some cash because the z32 sensor is like $170 and that is what everyone says to do

[NASTY]

LOL, sorry man, long night and I was little rough. The S14 tach can be calibrated without sending it in but it will not be perfect, my issue at the moment is I can't get it to budge.

Same thing with the speedo, but I am going by what I've been told. Again this is all for an S14 and will be different for the S13. I have a list of about 30 different places with mixed info. I've been trying to piece it together from all of that.

[HxC_Nismo]

double check your wiring from your m63 plug in your passenger side kick panel. make sure the pinned it right cause it sounds like there either wired wrong or you have a blown fuse. mine worked right off the bat and i just calibrated my tach to work and compared it to my apexi hand commander. you should not have to add any resistors or dakota digital stuff, it should work just fine on the s14.

[sepulchralx]

my tach/speedo works

how about this... go to page EL-76 on http://www.nicoclub.com/FSM/240sx/1995/EL.pdf

run a wire from pin 7 on the ecu plug to your M5 plug (splice into Yellow/Blue wire) on inst. cluster harness

hardwire your vss leads as shown in the diagram to your M9 plug.

I think its also important your ecu knows what speed you're going so make sure theres continuity from there to your Ecu pin 53

[DeformityX]

Allright guy your first post made it seem like you had no idea why they where not working you dont have to be an a$$

Also exactly you can send your tach in for $80 and get it calibrated right but it wont work right by itself, you STILL need to do something, i was typeing it out but forgot to add that in there as an option; sorry

Really? I didnt know the speedo worked with a RB25 sensor, please let me know it will save me some cash because the z32 sensor is like $170 and that is what everyone says to do

Itll work with the RB25 sensor in... it just wont read right... what hes saying is his gauges dont move atALL hes not even getting the 1.5 times read on the tach or the half read on his speedo...As for the speedo... best bet is find a 300zx N/a and pull the speed sensor... theyre all over the junkyards man...

[andy107]

my tach/speedo works

how about this... go to page EL-76 on http://www.nicoclub.com/FSM/240sx/1995/EL.pdf

run a wire from pin 7 on the ecu plug to your M5 plug (splice into Yellow/Blue wire) on inst. cluster harness

hardwire your vss leads as shown in the diagram to your M9 plug.

I think its also important your ecu knows what speed you're going so make sure theres continuity from there to your Ecu pin 53

Excuse my dumbness, but looking at the FSM and comparing it to Mitchell on Demand's wiring diagram. The VSS already is wired straight from the sensor to the connector on the cluster harness from the vehicle as with the tach signal from the ecu directly to the cluster. Unless there is anything in between the wiring that may interrupt both signals. I got everything working on my r33 cluster besides the speedo and tach. I gotta borrow a multimeter to see if I'm getting any signal from the ecu for the tach. Hope its not dead. lmk.

[Tenchuu]

i just re calibrated my stock S14 gauge. works like a charm.

[sepulchralx]

Excuse my dumbness, but looking at the FSM and comparing it to Mitchell on Demand's wiring diagram. The VSS already is wired straight from the sensor to the connector on the cluster harness from the vehicle as with the tach signal from the ecu directly to the cluster. Unless there is anything in between the wiring that may interrupt both signals. I got everything working on my r33 cluster besides the speedo and tach. I gotta borrow a multimeter to see if I'm getting any signal from the ecu for the tach. Hope its not dead. lmk.

Your speedo is not working because of your transmission harness connection to the fusebox. If you have your vss pigtail wiring on your stock lower harness prewired into your rb25 vss plug, then that is all it can be. Make sure you used your KA trans harness and not the RB.

For the Tach, that runs off the engine harness, you adjust the potentiometer to calibrate that.

[andy107]

Thank you sir. Both the tach and speedo works. Checked and fixed all connections. I had two yellow w/blue stripe gray dot leads on the R33 cluster for the tach. Not sure why but both show continuity on the ohm meter to and from the cluster, so I wired both to blue w/black stripe leads on the 240 cluster harness. Works great now.

As for the speedo I looked around the web and found where the speed input and ground is located for the VSS. "Pic shown on the bottom." Its not my pic but can't remember where I found it. Traced the input signal for the VSS on the R33 cluster to be gray w/red stripe. On my cluster I had two of the same gray/red stripe wires. One for the fuel gauge and the other for speed input. The gray/red stripe goes to the red/yellow stripe on the 240 harness. On the 240 harness there are two red/yellow stripe wires one from the VSS and the other for ground side cluster back light dimmer. Wired those accordingly. The red wire coming from the 240 harness is the ground side from the VSS. I found out it was ground by looking at my s14 cluster and traced the leads on the printed circuit to one of the "ground sided" screws holding the speedo gauge. Same went for the R33 cluster and found ground side VSS lead to be brown w/yellow stripe. Put everything back in and test drove GREAT. I don't know why Nissan uses two of the same colored leads for different components. For those who are doing this project. Don't forget to cap off "hot at all times or when on" wires such as the clock and lumination circuit. Use shrink wrap if possible.

The only thing I did not connect is boost, oil gauge, cruse and air bag light. I believe the cruse and air bag circuit on the cluster is different. I may be wrong. If you look at pic below, The air bag light has an external lead wired to the back side of the R33 cluster. Oil gauge needs oil pressure sensor from the RB or possibly a 300ZX. The 240 has only the pressure switch. Boost gauge needs the boost sensor and to wire that I may have to look at how the 300ZX is wired. Can’t seem to find a service manual for skylines on the cluster but seems that the nissans for the s14 generations are almost the same in some aspects. Looking at how the 300Z’s boost gauge is wired, there is 2 wires going directly to the cluster from the sensor and one wire for power. Total of 3 wires. Instead of using a 5 volt reference like most. This boost sensor seem to use full battery voltage with a 30amp fuse inline to it after splitting power to another relay for bulb check. Power, signal and ground are the 3 wires. Run wires from the sensor through your firewall to the cluster and match the color of the wire on the sensor pigtail and on your R33 cluster for ground and signal. Check by tracing the circuit. Then the remaining wire should respectively be for power if it is wired exactly like the 300zx. Don’t forget to add fuse if you are not tapping from the fuse box. This is all just an assumption, don’t take my word for it.

A little side note: Looking at 300plus.net’s diagram. The door light leads can be Blue w/red stripe for SE models and Red w/white stripe for others I believe. Also if your cluster back light don’t work make sure you are using the correct red w/blue stripe leads. There’s two, one for washer level and the other to power your cluster back light. The ground side of the back light uses 2 of the 3 ground leads on the R33 cluster going to red w/yellow stripe. Make sure its the correct ground lead by tracing the printed circuit next to the lettering “ILL-“ . I found out the hard way. Sorry if this is a long write up but I hope this may help someone. My wiring may be different compared to yours so its always good to look at wiring diagrams. Good luck.


Modified by andy107 at 9:16 PM 5/21/2009