Tach is working, no codes, the odometer seems to be working too. There's a few threads about this but most people had codes and no one ever seems to post a follow up to say what it took to fix it. Any thoughts? It started a few days ago, I noticed my speedometer was reading 0. Then 30 seconds later it was working fine. Then today it would randomly drop to 0 then start working again. Last light I stopped at tonight when it wen to 0 when I stopped, it didn't move off there the mile or so home.

 

Have u tried going faster?

 

So has the needle completely stopped registering speed now? If so did you try putting the cluster into diagnostic mode to see if it moves then? Since you're not throwing any codes and the odometer seems to be working, I feel you have another manifestation of the solder joint issues on the cluster PCB. That or the stepper motor is dying/dead.

 

First thing I tried!

How would I put the cluster in diagnostic mode? The needle just sits at 0.

 

Key in off position

Press and hold the odometer reset stick

While holding reset stick, turn the key to on to ON position. (Dont start engine)

Once the dash fully lights up, release the reset stick and press it 3 times quickly

All your mileage numbers should disappear. This means u are now in diagnostic mode

Now, when u press and hold the reset stick, all the needles should move to their test positions.

Heres a pic:

 

I put it into diagnostic mode, speedometer did move like in the picture.

Someone on Reddit said they had the same problem, they disconnected their battery for 30 minutes and that fixed it. So I did the same thing but also turned on the headlights and stepped on the brake to be sure there wasn't juice left. After that I did the diagnostic test. Took it for a drive, speedometer is working now. But obviously I need to keep an eye on it. Appreciate the help!

 

That;s crazy. I can't believe that fixed it. I thought for sure it was going to be another bad solder in the combo meter thing in which case it wouldn't move during diag mode. I hate it when reboots fix things because it just doesn't explain why it's bad in the first place....

 

Well, let's see if it works long term. But hopefully it does. Same thing with phones and computers, a simple reboot fixes the issue.

 

Later that night, my speedometer worked intermittently. But today its been fine. A friend that pretty much only works on this platform and the 350/370Z suggested checking the rear speed sensor/tone ring.

 

Yeah, I would have put money that the fault would have returned. If the odometer is still working when the speedo isn't then I still think it's a cluster issue.

 

Yeah I would check those two rear wheel speed sensors as well, particularly the HARNESS. Both sensors are attached to the two sides of the differential, they run into a single harness. Unplug it and see if the pins are corroded.

I'm sort of leaning towards a failing dash though, if the data was intermittent from the wheel speed sensors then there would be a mismatch compared to the fronts and the car would think the vehicle was sliding and would turn on the VDC stuff.

Alternately you could plug in an OBD2 scanner that can read realtime data and just go for a drive while monitoring wheel speed (wheel speed is only measured from the rears, not the fronts) and if it's sending data but the dash isn't working then it's probably the dash and my gut is saying the culprit would be the STEPPER MOTOR not a resistor.

If that ends up being the problem you can solder in a new stepper motor without needing to replace the entire cluster.

 

Swapping the stepper motor on these clusters is tough.

There are 6 solder points you need to melt simultaneously to get the motor off the board. On top of that there is super thin copper wire attached to the 4 posts of the stepper motor on the other side. Gotta be real careful not to break one of those.

 

Solder sucker, then you can do them 1 at a time to get almost everything removed. Heat them 1 at a time again quickly if they're not all free when you go to remove because there's usually a little bit stuck down inside where the wire tip goes through the PCB.

 

95% of the time the speedometer works. When it doesn't, its maybe a mile or less before it works again. Probably going to have my friend who works exclusively on these cars take a crack at it if I can't figure it out. Nothing under the car should be corroded, its a Texas car and always has been.

 

Cruise control works fine, oddly enough, yesterday afternoon on the highway with the cruise set at 78 (and remained constant on my GPS), the speedometer was slowly moving from 78-83 or so, sometimes staying at one speed a while, then slowly increase or decrease. However, that evening it was dead on with my GPS and didn't vary at all. Only variable I can think of; my headlights were on in the evening.