Hi guys

 

I have a small problem with the Zed again - the speedo stopped working (after no warning of an impending problem it became intermittent for a day then just seems to have given up) It just reads zero all the time now and this is messing up the power sterring too.

 

I know there is a possible issue with a bad soldered joint inside the speedo but what has me wondering whether that is the problem is because I also have a separate aftermarket digital speed meter/timer and that has stopped working as well. I think the problem is more likely with the speed sensor and/or km to miles converter but have no idea where to even look for either of those

 

Any advice?

Cheers

Rich

Hi Rich the speed sensor is in the gearbox and the kph convertor is the little black aftermarket box behind the dash binnacle.

Where did you take the feed for the digital speed meter?

 

Here are some coloured wiring diagrams which may help you see the route from the source http://www.300zx.co.uk/forums/showthread.php?151003-Colour-wiring-diagrams

I think the problem is more likely with the speed sensor and/or km to miles converter but have no idea where to even look for either of those

 

Speed sensor is located on the gearbox here:

 

 

Make sure the wires going ino the sensor body are not damaged.

 

And is tested in the FSM like this:

 

el-44.pdf

Here bud this may help you out

 

The unit is a small pulse generator, as the cog is turned by the gearbox the stator is turned within the field windings which produces a small ac voltage of around 1 to 5 volts and as the unit is very unstressed there is very little that can go wrong with it.

 

However the unit is held together by the black plastic end cap, this end cap is where it all goes wrong, for reasons unknown the caps start to come adrift as seen in the photo.

 

This loosening of the end cap allows the stator shaft / field windings to move out of line not by much but enough to stop the output been produced.

 

Annoyingly as the cap originally starts to slowly moves out, the shaft end float is still small enough for it to move in and out of the correct position and so causes it to work intermittently.

 

So armed with this information all you need to do if faced with this problem is get the car jacked up and take a look at the end cap on the sensor, if it looks like the faulty one in the picture simply apply a layer of epoxy resin to the edge of the cap and push it back in, yes that simple, no need to even remove it, and you will have one fixed sensor for a tube of glue.

Right guys that should help :)

 

I didn't fit the aftermarket KM/MIles converter as it was already fitted when I got the car

 

Sounds like the problem described above, or maybe a dodgy wiring connection

 

Cheers

HI guys

 

Unfortunately I still don't have this sorted. Got the car on the ramp at the garage across the road at the moment. They took the speed sensor off for me. It doesn't look like the faulty one in the pic and I tested it on an AC volt meter as advised and I read about 1.5V AC on the terminals when it is rotated by hand. So I guess that means it is OK.

 

Next thing I guess is either a bad connection or broken wire. I have a km/miles converter which is behind the clocks somewhere though i didn't fit it. I guess I am right to assume I should see a voltage there if I spin the speed sensor - anyone know which wire is the one coming from the sensor or what a km/mph converter actually looks like?

 

Thanks

Rich

Speed converters are notorious mate.

Rich I might have a set of UK clocks in a box somewhere you can try fitting and see if it fixes ghetto issue. What year is your car ?

Hi Ian, it's a 1993 - but I don't think it is the clock, as I have a separate digital timer/speed meter and that is reading zero as well. Also the power steering feels weird.

 

I will get behind the clocks and see if I can find the mph converter. Looking at one on ebay it seems to be a little box with four wires - sensor in, 12v, 0V and output to speedo? At least then I can get someone to spin the speed sensor at the gearbox and see if I can read a voltage in and out of the converter.

 

If I can't find it I will take some pics of what is behind there

 

Rich

Hi Ian, if dicky does not have your clocks , I would be interested , LEt me know pls

Guys

I got the dash clocks out but I can't see anything behind there that would look like a kph/mph converter.

 

To be honest I feel this is getting beyond my ability to fix - I am very good with electronics but not with cars :no: I now hav about a zilion screws and I hope I can rememebr how it all goes back together!!!

 

Here are some pics of what I can see from behind the clocks. This things with the green arrows are the power and switch (green/blue) for my electroflourescent dials

 

To add to my woes I moved the drivers seat back so I could easier work on the dash and now the bloody thing wont move forward again (electric) I had this problem a few years ago as I recall but can't recall how I fixed it.

 

I really love this Zed but sometimes it is a difficult relationship grrr

The seat: Check fuse first obviously. But if no joy you need to get the footwell fuse panel out. You need to unplug everything, unscrew it and pull it out so you can get to the back of it. Loads of typical square relays on the back. But in the middle there is a round one. This is the circuit breaker for the windows and seats. It's a bi-metalic cut out device & i bet its that thats gone.

 

 

 

 

Guys

I got the dash clocks out but I can't see anything behind there that would look like a kph/mph converter.

 

To be honest I feel this is getting beyond my ability to fix - I am very good with electronics but not with cars :no: I now hav about a zilion screws and I hope I can rememebr how it all goes back together!!!

 

Here are some pics of what I can see from behind the clocks. This things with the green arrows are the power and switch (green/blue) for my electroflourescent dials

 

To add to my woes I moved the drivers seat back so I could easier work on the dash and now the bloody thing wont move forward again (electric) I had this problem a few years ago as I recall but can't recall how I fixed it.

 

I really love this Zed but sometimes it is a difficult relationship grrr

The seat would drive backwards but not forwards so it does have power to it.

 

Anyways this morning I tried holding the switch on the seat in the forwards direction (no joy) while simultaneously shaking the seat violently and lo and behold it then moved forwards and it now seems to work fine. Go figure that one!

 

I put the dash pretty much back together but I have got a problem with the left hand barnacle. The hazard flasher switch was held in place wih two long screws about 2 inch long and they unscrewed all the way out with no problem but when I tried to screw them back in they just push all the way down the plastic tubes they should screw into and will not grip at all. I know they are the right screws as they are the only long ones. So that is all hanging loose at the moment. What's gone on to cause that? It's wierd.

 

The missus wanted to go to the garden centre this afternoon and as my van was in the garage having a new fan and fanbelt fitted I decided to take the Zed even though the speedo was not working and the steering is heavy. Anyway all the way there (about 5 miles) the speedo would not work, but when I set out back it started to work again of it's own accord and kept on working all the way home. I don't trust it though, I bet it will stop working again.

The seat would drive backwards but not forwards so it does have power to it.

 

Anyways this morning I tried holding the switch on the seat in the forwards direction (no joy) while simultaneously shaking the seat violently and lo and behold it then moved forwards and it now seems to work fine. Go figure that one!

 

I put the dash pretty much back together but I have got a problem with the left hand barnacle. The hazard flasher switch was held in place wih two long screws about 2 inch long and they unscrewed all the way out with no problem but when I tried to screw them back in they just push all the way down the plastic tubes they should screw into and will not grip at all. I know they are the right screws as they are the only long ones. So that is all hanging loose at the moment. What's gone on to cause that? It's wierd.

 

The missus wanted to go to the garden centre this afternoon and as my van was in the garage having a new fan and fanbelt fitted I decided to take the Zed even though the speedo was not working and the steering is heavy. Anyway all the way there (about 5 miles) the speedo would not work, but when I set out back it started to work again of it's own accord and kept on working all the way home. I don't trust it though, I bet it will stop working again.

 

This is exactly what mine used to do. I took the speedo out one day and that making and breaking of the contacts seemed to do it good. Haven't had the problem since.

Lee Dent now has it.

 

Although the speedo worked on the way back from the garden centre yesterday it didn't work when I started the car today nor did it work all the way to Shrewsbury

 

Rich

I took the speedo out one day and that making and breaking of the contacts seemed to do it good. Haven't had the problem since.

 

I think this is spot on advice, the cluster needs just sitting down with and going through it all - sure Mr. Dent will find it in no time but i must say Rich i thought a man your skill would of sorted this :cool:.