No speedo & erratic fuel gauge

The speedo on my wifes micra (1 ltr, '98) stopped working last night.

I expected to find a loose connection but everything seems fine.

Also noticed that whilst driving the fuel gauge is moving from the level in the tank down to empty and then back and back down...

Temp gauge is reading normal.


Things I have check so far:

12V to speedo unit in gearbox OK (between yellow & black wire)
Gear on on of unit OK
Connection on back of instrument cluster OK

Can anyone tell me the output from the gearbox unit, is it mV, mA or something else, or if the fuel gauge and speedo can be in some way related ? perhaps an earth issue ??


The fuel gauge is only moving while the car is moving, therefore I think the speedo signal is somehow interfering with it ????


Many Thanks
Chris

Speedo fault identified !

Seperated the speedo drive unit and found the shaft between pinion and magnet had snapped, and all the plastic had melted.

Trip to scrap yard required :grinning:

All fixed, replacement speedo drive unit £5 from scrappy, fitted this which also cured the erratic fuel gauge !

Hi guys,

I think I have the exact same problem as CB_182.. have checked what he has said and seems identical. So i'm going to get a replacement speedo drive unit. (How much are they if I cant find 1 in scrappy?)

Also, I'm not exactly a mechanic.. but I can do the normal stuff like brakes etc.. how hard is this job going to be? I gotta get it done this weekend.

Look forward to some feedback.

cheers.

*bump*

Hi, I paid £5 for one, not sure the guy new what it was or if it should have been anymore than that anyway.

Also, it was easy to do one bolt holds the unit in from above and then i carefully prised it up with a large screw driver from side to side.

P.S put a rag around it or on the floor as when it does pop out you will spill some oil.

hi CB 182, thanks for your reply.. Underneath the Engine there is 2 that look similar.. is the the once closest to the front of the car? or the one near the back of the gear box?

Having real trouble trying to find one at the moment, any ideas on where I can look?

sundog1 said:

hi CB 182, thanks for your reply.. Underneath the Engine there is 2 that look similar.. is the the once closest to the front of the car? or the one near the back of the gear box?

Having real trouble trying to find one at the moment, any ideas on where I can look?

Click to expand...

sundog, the speedo drive is on the top of the diff (near the bulkhead) but you need to test whether the cable is spinning or not first (assuming yours is,nt digital)

Its a 2000 W Reg K11, I believe its digital.

sundog1 said:

Its a 2000 W Reg K11, I believe its digital.

Click to expand...

oh, yeh, it should be, i think the sender is in the same place tho, and you,re best to check for a signal from the sender, before you start buying parts imo

ok, thanks for you advice I might get that checked tomororw. will be back in touch as soon as found out.

Threada dead baby!

Anyway i have this problem, exact same symptoms.

Speedo failed and sits at 0mph. fuel gauge i can watch in real time going from half full to near empty.

Odometer has stopped working aswell. iv put another set of clocks in but no joy.

Any thoughts @frank

I had this before when I'd blown a fuse.

Though a fuse wouldve stopped trhe whole cluter not just the speedo and trip and fuel lol

Ah, no idea then mate haha!

sundog1 said:

Its a 2000 W Reg K11, I believe its digital.

Click to expand...

Digi speedo unit is on top of the gearbox, one 10mm bolt securing it. Once the bolt is out the unit can be quite stubborn to remove, I found using pliers/grips from the side, twisting gently a little in either direction while pulling upwards the unit would come out easily, yes watch out for a little seepage!

Sorted, was indeed that speedo drive. cars all fixed and up for sale now haha