No light on speedo gauge and electronic speedo goes out ?

[Mr Plow]

Hi All

For some reason I have no light on my speedo gauge, I've checked the bulb, its OK. The electronic mileage reading disapears when you turn the ignition on?

Any ideas, could the two be connected?

Cheers

Liam

Edited by Mr Plow on Thursday 3rd April 20:13

[Mr Plow]

Thanks for the reply.

I've done some more investigation work, it is definately not the bulb, I have tried a couple.

So..

With the ignition turned off the electronic mileage shows. As soon as you turn the ignition on the mileage dissappears, it stays off when you start the car. When you drive the car the speedo doesn't work.
If you turn the lights on, all the gauges illuminate except the speedo.

Does any one have a wiring diagram or any advice, it looks like when the ignition is turned on a feed somewhere changes stopping it from working. I've had the centre console out and the dash top off so maybe I've knocked something, but what?

Cheers in advance

Liam

[Mr Plow]

Fixed

Bad earth, added a new earth and all is OK.

Thanks all

Liam

[Mr Plow]

Update on the below, all is not quite OK with a new earth fitted.

Lights are fixed, mileage reading is fixed, however the speedo isn't working, the needle doesn't move and the mileage doesn't change.

Any ideas?

Cheers

Liam

[Mr Plow]

Further update, I've checked the wires on the connector, they are showing as follows:

Black - Earth
Green - Ign 12v
Red - perm 12v
red/white - lights on 12v
blue/yellow - goes into the box marked MO559 which I believe is the speed transducer?

Is there an easy way to check the blue/yellow wire?

Not sure where to go from here, I'd like to at least work out if it is a wire, or part at fault.

Any suggestions appreciated.

Cheers

Liam

[Mr Plow]

Hi All

Another update. I've changed the speed sensor, still no joy.

When I turn the ignition on the speedo needle moves very slightly, I think this rules out it being the speedo head?

Have I connected something incorrectly if the needle is moving when I turn the ignition on?

I'm at the point where I might need to call in an auto electrician, I rather sort it myself though if I can.

Any other ideas?

Cheers

Liam

[Mr Plow]

OK, so I've had an auto electrican round this afternoon.

THe speedo sensor is sending a signal through the the box that is sending a signal through the speedo. Its the actual speedo that has had it and needs repairing. I'll be sending this off as soon as I can.

I understand they can take a while to come back, does anyone have a spare one lying around that I could buy or even borrow until mine is fixed? Or know where I could get one from? Its the newer one with an electronic mileage reading.

Cheers

Liam