HZJ80 Instrument cluster (2 Viewers)

[boozewz]

Just got a 1990 HZJ80, and the instrument cluster has gone kaput. The truck runs on a 24V system. I managed to source a used complete instrument cluster from a 1996 FZJ80. Upon opening them both up, I found some differences, most notably in the speedo meters.

Anyone know whats the additional odometer on the top of the FZJ80 cluster?

Also, would the FZJ80 cluster work on the HZJ80 with its 24V system?

Cheers

HZJ80 cluster (no gauges are working...notice 3rd odometer)

FZJ80 cluster

 

[Douglas S]

You sure it's 24V?

 

[IanB]

Extra odometer might be for the change timing belt dash light?

And I also think that it might be just the starter that's 24v on that truck.

 

[mac]

You should be 12volt on your cluster. If your whole cluster is not working it's probably not the cluster but a central wiring issue. Check your connectors at the back. Your speedo doesn't work either? It should be cable operated on your HZJ. The FZJ uses a VSS so for it to work you would need the pickup and wiring associated with it. The tach will not work with your diesel either.

 

[boozewz]

You sure it's 24V?

Extra odometer might be for the change timing belt dash light?

And I also think that it might be just the starter that's 24v on that truck.

Forgive my ignorance, I'm no electrician, but whats the easiest and quickest way to check if its 12v or 24v? Its got two 12v batteries, but other than that I'm clueless.

 

[boozewz]

You should be 12volt on your cluster. If your whole cluster is not working it's probably not the cluster but a central wiring issue. Check your connectors at the back. Your speedo doesn't work either? It should be cable operated on your HZJ. The FZJ uses a VSS so for it to work you would need the pickup and wiring associated with it. The tach will not work with your diesel either.

Thanks Mac...I am not ruling out the possibility of the PO having swapped out the cluster previously with a FZJ cluster, hence them not working when I bought the HZJ80. On the other hand, we plugged in the FZJ cluster I picked up from the junkyard and all gauges were working except the RPM gauge.

I'm trying to source an RPM gauge seperately, which is why the instrument cluster has now been taken apart as can be seen in the above picture. What could be a reason the tach wont work?

Cheers

 

[Spin]

Extra odometer might be for the change timing belt dash light?

And I also think that it might be just the starter that's 24v on that truck/QUOTE]

Spot on, that is what it is for.

Spin

 

[mac]

Thanks Mac...I am not ruling out the possibility of the PO having swapped out the cluster previously with a FZJ cluster, hence them not working when I bought the HZJ80. On the other hand, we plugged in the FZJ cluster I picked up from the junkyard and all gauges were working except the RPM gauge.

I'm trying to source an RPM gauge seperately, which is why the instrument cluster has now been taken apart as can be seen in the above picture. What could be a reason the tach wont work?

Cheers

Your rig will be 12volt. If you look at how the batteries are connected you'll see that + goes to + and - goes to the body/ground.

You can try removing the tach from the HZJ cluster and installing it in the FZJ cluster. The diesel tach uses a different signal than the gasser. It comes from the back of the injection pump.

 

[boozewz]

Your rig will be 12volt. If you look at how the batteries are connected you'll see that + goes to + and - goes to the body/ground.

You can try removing the tach from the HZJ cluster and installing it in the FZJ cluster. The diesel tach uses a different signal than the gasser. It comes from the back of the injection pump.

Cheers Mac....the tach on the HZJ wasnt working when I took delivery of the truck, which is why I'm looking for a new/used tach. Will look into it and let you know how it goes.

(I noticed the poverty pack models dont have tach's, but have the fuel gauge and the water temp in place. So technically I could go that route, although I suspect the whole instrument cluster would be different rather than replacing a tach dial with a fuel/temp dial).

 

[mac]

Are you sure it's the tach and not the sender?

 

[boozewz]

Are you sure it's the tach and not the sender?

This is what the truck came with



And this is the one I pulled off a FZJ80 from the junkyard


Edit: Is there a possibility that the 1990 HZJ80 did not come with the instrument cluster seen above?

 

[girraffe]

The top odo on the HZJ80 is for the timing belt light. Remove the plug on the clear plastic and press in the button and it resets the light for another 90k kilometers or whatever the change period is. An easy way to check your "in cab" vltage would be to open your fuse box and check voltages in there.

 

[mac]

If you have poverty packs over there without tachs it's possible that your HZJ never had one and someone had that cluster swapped in. It does appear to be showing an RPM though- 400? Have you checked to see if you have an RPM sender on the back of your pump?

 

[boozewz]

Is this the RPM sender at the back of the pump?

Well spotted on the 400RPM..That tach was not working, and the needle is stuck on 400RPM

Some not so good news: installed the FZJ80 cluster in the HZJ and none of the gauges are working except for the voltage gauge. The tacho, speedo, fuel, and oil are not working. However, when the ignition is on, but the truck is off, all the lights in the cluster come on.

I guess my "find" at the junkyard was not really a find as it may have already been damaged. That still doesnt help me explain how all the lights came on. (when I used the turn signals, the blinking arrows are working etc)

 

[girraffe]

Hey you can go to the diesel section and at the top there is a link fo getting the factory service manuals. there is one there for the 1990 hdj/hzj80. It has the electrical wiring diagrams that show how your gauge cluster is wired.

Found this and looks like its is attached to the block somewhere.

 

[boozewz]

Hey girraffe....much appreciated!

If the gauges are not working, and I dismantle them from the cluster, would there be a way to repair them? Or once they're toast thats it they need to be replaced?

 

[finderscuba]

The fact that the voltmeter only goes to 18V proves this is a 12V truck. In fact, I do not believe there is a factory 80 Series in full 24V in existence.

The rpm pick-up sensor is on the engine side of the pump. I believe what you're holding in one photo is the fuel cut solenoid (minus the rubber boot). Here's a snip from the FSM:

 

[boozewz]

The fact that the voltmeter only goes to 18V proves this is a 12V truck. In fact, I do not believe there is a factory 80 Series in full 24V in existence.

The rpm pick-up sensor is on the engine side of the pump. I believe what you're holding in one photo is the fuel cut solenoid (minus the rubber boot). Here's a snip from the FSM:

Yes sir thank you for that. You're right, we did a compression test today and we figured out that its the fuel cut solenoid. We ended up crimping that wire as the two ends where duct taped together by the PO

Had a look around the back of the pump, facing the engine but did not notice a sensor or a wire back there for the RPM pick-up. I did however notice a open ended plug attached to the same wire of the fuel cut solenoid, coming out of the firewall. Could this be what the RPM pick up is supposed to attach to?

As for the voltage, finally figured it out. Its a 12V setup with a 24V alternator. (+ve on both bats are connected to each other while the -ve on the passenger side battery is grounded to the frame).

 

[finderscuba]

Had a look around the back of the pump, facing the engine but did not notice a sensor or a wire back there for the RPM pick-up. I did however notice a open ended plug attached to the same wire of the fuel cut solenoid, coming out of the firewall. Could this be what the RPM pick up is supposed to attach to?

As for the voltage, finally figured it out. Its a 12V setup with a 24V alternator. (+ve on both bats are connected to each other while the -ve on the passenger side battery is grounded to the frame).

It's not the alternator that's 24V, it's only your starter. There is a series/parallel switch that applies 24V to the starter when cranking. Everything else on the truck is 12V. Everything!

It looks like that plug is for the tachometer pick up sensor. At least according to this diagram from the FSM:

 

[boozewz]

It's not the alternator that's 24V, it's only your starter. There is a series/parallel switch that applies 24V to the starter when cranking. Everything else on the truck is 12V. Everything!

It looks like that plug is for the tachometer pick up sensor. At least according to this diagram from the FSM:

Sorry I meant the starter:whoops:

Do you have a pic of where the sensor is located? All I would have to do is purchase and attach the sensor in its location and plug it in to the wire in the pic above? Is it that simple a fix?