Afetr my xarry on with the speedo working, I decided to get under the dash and see what, if anything, I could find.

 

I appear to have a switch cut into the circuit of the speed converter?? cant think why you would want to do that.

 

I also found the box shown in the picture, underneath the drivers side. It has six wires plugged into it, three of which have been cut. One of the remaining three is an earth. Any clues as to what it is or why anyone would chop it?

 

Cheers

 

Hugh

bong bong bong bong, looks like the really anoying speed warning bonger that is fitted to Jap vehicles. Wires are cut to stop it from working. Don't know why there is a switch on the converter, how many wires on the converter? There is usually only 4 wires, +ve -ve pulse in pulse out.

If you are having speedo problems I would suggest removing the converter temporarily from the speed pulse circuit wire.

 

Paul (SparkZ)

The speed converter itself is a bit of a mystery, I traced the wires that were cut into the speedo and they, amongst others, ended in this abortion. Which is sealed in Heatshrink, has 5 wires from it , one of which is cut short, two go to the speedo, the other two???

I thought this ( at the top, behind the dash) was the Bong, Bong thing

Not sure about the bong bong thing then, been a while since I'v seen behind a Z dash.

 

I guess the speedo converter is a universal one with separate wires for a delimiter, they use them on GTO's and other cars but shouldn't need it on a Z. Trace the non red and black pair that go to the speedo. Cut the wires that have been cut in to the existing loom and join them. If that cures your speedo problem then you know the cause.

 

Does the speedo die for a while and then come back?

Does the Hicas go mad when it happens?

Does the engine check light come on?

 

Or does the speedo dance about like a freak on speed but no other side effects?

 

Paul (SparkZ)

Got an NA so no hicas problems

 

NO engine check light

 

The speedo is dead 90% of the time, the other 10% works perfect, no inbetween, either on or off