R34 Gt Speedo Not Working

[SteveOsteve]

Hey guys,

I recently installed a new cluster and when i went for the first drive everything seems to work fine except for the speedo.

i cant seem to work out whats wrong with it, all the other gauges work fine, i just cant see the speed im travelling.

any help would be great

[Ben C34]

Put old cluster back in.

How do you know the new cluster works?

[sleptema]

If you are sure you have installed correctly - cluster is broken more than likely.

Was the cluster new or used?

If the old cluster works, then everything car side should be fine.

Edited October 3, 2014 by sleptema

[SteveOsteve]

it's a used cluster off a GTT my 34 is GT could it be that ?

if it is broken can you get them fixed ?

I really like this one never seen one like it before

[sleptema]

Right, school holidays.

I get it now.

[SteveOsteve]

??

[toranarod]

Are Gtt instrument cluster compatible with non Gtt electrical systems The Gt  RB25de?

I am converting a Auto to a manual.

 My auto  has low ks and the manual cluster has almost double that. What would happen if I swapped the processor chip on the main board over. Looks like the ODO memory is kept in the main processor. Has this ever been done before.      

[toranarod]

I purchased a cluster and the Speedo didn’t work. Then I got another cluster worked fine and so did the original.   This is getting confusing but to cut to the problem my auto has low ks and the manual cluster has almost doubled that. What would happen if I swapped the processor chip on the main board over? Looks like the ODO memory is kept in the main processor. I think the main processor is good because the instruments work except for the speedo what believe is happening the signal data coming from the gearbox is being lost in the board before it gets to the CPU than runs the whole show.

Or is it the signal coming from the gear box are not compatible with a NA instrument cluster

[jrm]

Not sure if this is much discussed around here, or how legal this is - but there's a lot of information around online anyway.

Odometer data on most of these cars is stored on an 8-pin EEPROM inside the dash cluster.  It's on the inside side of the board - so you'll need to remove the PCB fully to get to it.  It's typically something like an 93c56 EEPROM chip.

Inside the chip, the data itself is stored in a certain way with checksums, etc that some people have figured out how to re-write the odometer data successfully - using an EEPROM programmer (like a TL866II Plus).

Having said all that, it should be possible to simply desolder the chip from one dash cluster and swap it into another dash cluster. For ease of swapping them - you could even put an 8-pin DIP socket in its place to make it easy to swap in and out in-case you needed to reverse it for whatever reason or it didn't work.

I can't say what other configuration information may be stored on that chip which may affect operation, and I've never personally done it - but if you're desperate - this is something you might consider.

This thread has some additional information that may help: