The speedo on my convertible ZX keeps dropping to zero now and again, sometimes it's ok but sometimes it will also be stuck on zero!! had a customer wishing to collect today but he couldn't because of this problem. The car never had this problem on the car before today so it's incredibly bad timing to go wrong, ie at point of sale!! I'm thinking perhaps the cold weather has had an adverse effect on the speedo chip??

 

So I have changed over the gearbox speedo sensor but it is still doing the same... I am sure it is the delimiter chip gone faulty, does that sound right because I don't really want to open up the dash for no reason...

 

Anyone got/had the same problem and what did the fault turn out to be? Thx Lee

OK this is going to be no help at all but i have had the same problem once or twice on Cold mornings! I would start up and Speedo wouldnt move for about 5mins of Driving (After Warmed up) and would bounce about for abit but then would be fine afterwards! On normal mornings it is fine so maybe just give it abit of a run about!

OK this is going to be no help at all but i have had the same problem once or twice on Cold mornings! I would start up and Speedo wouldnt move for about 5mins of Driving (After Warmed up) and would bounce about for abit but then would be fine afterwards! On normal mornings it is fine so maybe just give it abit of a run about!

Sounds like you have the exact problem as mine!! wonder what the exact fault is...

I had the same problem, occasionally gave the top of the dash a bang and it would work.

Usually a dry joint, but after fitting a new kph to mph convertor, never had a problem

I had the same problem, occasionally gave the top of the dash a bang and it would work.

Usually a dry joint, but after fitting a new kph to mph convertor, never had a problem

Thanks, but how would spot a dry joint? I have got someone booked in tomorrow to replace the converter but at will cost me £100, so hope that it solves it!!

You cant really see a dry joint, its usually in the make up of the solder ie: internal make up of the flux. The convertor is really easy to fit, and the convertor is available for about £20 buy it now on ebay. If there is a convertor fitted already then check the point where it has been spliced to the speedo wire.

 

You can do a search for speedo convertor which will show the wiring

Hope this helps

You cant really see a dry joint, its usually in the make up of the solder ie: internal make up of the flux. The convertor is really easy to fit, and the convertor is available for about £20 buy it now on ebay. If there is a convertor fitted already then check the point where it has been spliced to the speedo wire.

 

You can do a search for speedo convertor which will show the wiring

Hope this helps

I have a spare chip but it's from a TT manual, so don't think it will work on the auto?

are you talking about a chip for the ecu?

the problem is More likely behind the dash

are you talking about a chip for the ecu?

the problem is More likely behind the dash

No I meant to say I have a spare speedo converter chip, but it was originally fitted to a TT manual? should it make any difference?

If its the little black box converter then its for either as it just converts the voltage/ohms

If its the little black box converter then its for either as it just converts the voltage/ohms

Yeah it's the little black box converter, so it should work?

yeah no probs

yeah no probs

Many thanks:), your help much appreciated :bow:

Anytime..

Just a little tip on fitting, make sure you secure the little box, either cable tie or velcro glue gun etc.. if its left just sitting behind the dash, it will move about a bit with driving around and with the added movement or banging around, can dislodge a wire or one of the components inside the box which would eventually cause failure..

Anytime..

Just a little tip on fitting, make sure you secure the little box, either cable tie or velcro glue gun etc.. if its left just sitting behind the dash, it will move about a bit with driving around and with the added movement or banging around, can dislodge a wire or one of the components inside the box which would eventually cause failure..

Thanks, and that's probably what has happened to this car, also the chip was fitted in 2003 so maybe the age factor has caught up with it too...

Tried the second chip and it was doing the same... then I by-passed the chip by re-connecting the green wire and annoyingly there was still no change!!

 

I then decided to open up the speedo and to check the circuit board, I checked for dry joints, and whilst i'm no electrician I just looked for the solder points which didn't look so good... I could see that some of the larger lower solder points looked quite "greyish and dull" and these were the one's I focused on...

 

All in all I resoldered the the furthest bottom 4 points and a few around the top and hey presto it's now working perfect!!, quite pleased with myself as I have saved myself a £100 odd quid which wouldn't have solved the problem anyway!! and I will have a happy customer :cool:

Brilliant news.....Speedos never used to bother me

 

but nowadays theres nothing worse than passing a speed camera with no-one in front of you to guage what your doing :rofl:

 

It's fine if you know what revs=speed, but if you've never bothered to look before your as well stopping at the camera...pushing it through....jumping back in afer all the white markers and driving off :rofl:

Dry joint after all, glad you got it sorted Lee.

Dry joint after all, glad you got it sorted Lee.

Thanks, if I get this problem in the future i'd probably take it to a proper electrcian and get them to check it thoroughly but I made do with a simple solderer and some "guess work"!!:)

Just to be sure, reflow all soldered joints. I've done loads recently. Getting more and more common. After doing it by looking for bad joints and just doing them, the damn thing not working, then doing ALL the joints and it has always cured it....

I've got the same problem with My Z and it's got worse this winter.. Was gonna go and buy a new speed sensor from nissan but there £153.64 ex vat! Speedo works fine in the summer and it's just the cold shitty weather that affects it.. Might have to rip my dash out now and resolder all the joints if it's more likely to be that rather than the speed sensor...

I'd deffo say it was the speedo rather than the sensor Jon. The cold weather makes the circuit board contract and makes the dry joint show itself....

I'd deffo say it was the speedo rather than the sensor Jon. The cold weather makes the circuit board contract and makes the dry joint show itself....

 

Cheers Andy, your a star! I'm gonna have a go at this tomorrow when I've got more time!

You've gotta be right as when there is any warm weather it works fine all day! Any misty, cold, rainy or foggy weather then it just dies or shoots up off the clock... Also if i hit a bump in the road it can go from working to tits up!

 

The Z then cuts out when the boost loads up to 1Bar as if i'm getting boost cut and also the fuel economy seems worse and the steering goes heavy! Not nice! Checked the speed sensor several times and the connecting wire is fine with no cracks and the sensor itself looks well in there so no water can penetrate..

Cheers Andy, your a star! I'm gonna have a go at this tomorrow when I've got more time!

You've gotta be right as when there is any warm weather it works fine all day! Any misty, cold, rainy or foggy weather then it just dies or shoots up off the clock... Also if i hit a bump in the road it can go from working to tits up!

 

The Z then cuts out when the boost loads up to 1Bar as if i'm getting boost cut and also the fuel economy seems worse and the steering goes heavy! Not nice! Checked the speed sensor several times and the connecting wire is fine with no cracks and the sensor itself looks well in there so no water can penetrate..

Definately sounds like the speedo circuit board to me... i'm quite pleased that with the help of club membesr we've managed to really pinpoint a problem that a lot of others have had!! I tried the car first thing in the morning today when it was cold and windy and the speedo is nice and smooth and working perfect:)

If the speedo is bouncing up to full then its DEFFO dry joints on the speedo board ;)

hey guys, my speedo died completely today after doing about 100 miles (mainly motorway driving). My steering became heavier and then my hicas light came on, at this point i pulled over to switch of my engine, leave it for awhile and then start it again hoping it might sort itself out temporarily (enough to get me home). The speedo was still down, but my streering was back to normal again for a short while until i hit faster speeds (60mph maybe??), my hicas light didnt come on again.

 

Also, (i dont know whether this might be related) my revs sometimes drop really low or my engine dies sometimes when pulling upto a junction or after pushing the car a little and putting the clutch in? this has been happening for a couple of weeks now on and off.

 

Ive been told that it might be my speed sensor that needs replacing as all these things are pointing towards a fault with it, but could anyone tell me if 'dry joints' in my speedo (or any of the dash cluster) could be the cause?? would it be worth re-soldering the cluster??

 

If anyone can give me any other advice on any potential problems and solutions id greatly appreciate it (like possibly resetting the TPS and base idle??).

 

Cheers guys

 

ps apologies for the essay, would have started a new thread but i saw this one and thought it may be the cause of my problems