# Cluster swap



## S3anpow (Aug 7, 2017)

I bought a 89 pickup with a 95 dash but the tach isn't working nor the speedometer how can i Fix this?


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## smj999smj (Jan 1, 2006)

Well, this could be two problems or just one. Tachometers due have a tendency to go bad on these vehicles and they are very expensive new from Nissan. Speedometer failures are also very common in many mid-90's Nissan models. It could be a stripped pinion gear on the pinion assembly on the trans or a faulty pinion assembly (vehicle speed sensor). More commonly, the threaded inserts on the back of the speedo head unit develop cracks, causing the bolts that attach the head to the back of the cluster to loosen up. When they get loose, the create a poor connection with the printed circuit, causing the speedometer to not operate or operate intermittently, which also effects odometer operation. The best thing to use to check the VSS signal is an oscilloscope, but most don't have that at their disposal. In a pinch, you can use the AC voltage setting on a multimeter to check for an output signal. The VSS is essentially an AC voltage generator that increases its output voltage with speed, approximately 1-volt for every 10 MPH. You can unplug the harness connector at the VSS and with the vehicle supported safely off of the ground so the drive wheels aren't contacting it, you can run the vehicle in gear and simultaneously monitor the AC voltage reading from the VSS. If no voltage, you know you have a problem with either the VSS, the plastic gear on it, or, less likely, the drive gear in the trans. If you have good voltage that increases/decreases with speed, then you can pull the cluster and, after plugging the VSS back in, check for voltage at the two, appropriate circuits that go to the speedo head. That will check the circuit between the head and the cluster. If that looks good, you can tighten the bolts on back of the cluster for the speedo head and see if they are loose as well as see if it gets the speedo working. If the speedo doesn't work and the odometer does, it's a faulty cluster. If neither work, it's likely a faulty speedo head, but I would first check your fuses and cluster grounds; actually, it might be a good idea to check your fuses, first, before getting too deep in this. If you have the cluster out, check for any burn marks on the printed circuit. You'll need a wiring diagram to locate the grounds; I highly recommend getting a factory service manual as it will be a wealth of information for you and will give you the wiring diagrams, connector views and diagnostic procedures you'll need now and in the future. It wouldn't hurt to check Nico Club's site to see if they have a free, downloadable manual, but it may be a little too old. Paper factory manuals, which I find easier to use, can sometimes be found on Ebay for around $25-35. If the speedo head is bad, companies like Mr. Whizard and Circuit Board Medics (Google them) can repair them. It will probably be an obsolete part as far as new Nissan part goes. Salvage yard speedo heads are a gamble as so many of them had problems.


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## S3anpow (Aug 7, 2017)

Thanks
But do you also have a label for the fuse box?
And where on the vg30i engine can i find the temperature sensor that connects to the ecu?


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## jp2code (Jun 2, 2011)

You did the Round Dash Swap on your 89 with 95 parts?

Did the Speedometer and Tachometer work in your 1989 before and go out just recently, or are you having an issue getting these new parts to work on your swap?

For the swap, you would need to change out the speedometer gear and wiring. The 1989 uses a cable and the 1995 uses a wire.

Like smj mentioned about before, the speedometer and tachometer do go out on these clusters, so you could have purchased a bad cluster.

Sometimes on a bad cluster, you can clean up the terminals, snug down the screws, and they will work again.

Instrument Cluster Repair w/pics (Part II)


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## smj999smj (Jan 1, 2006)

S3anpow said:


> Thanks
> But do you also have a label for the fuse box?
> And where on the vg30i engine can i find the temperature sensor that connects to the ecu?


Try looking for the ECT sensor at the front end of the left bank cylinder head, sorta hiding behind the rear timing cover. The two-pin sensor is for the ECM and the one-wire coolant sensor is for the gauge. If you don't have a label, just take a 12v test light and run it across the two contact points on each fuse with the key "on." Sometimes it's quicker and easier to use that method that it is to find a specific fuse! FSM would show the fuse layouts.


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