172 dash needles are not moving SOS

[Gus]

Massive problem with getting a mk2 172 ready for an MOT. The dash needles are not moving when you turn the key on.
Rpms
Speed
Petrol
Coolant.
They do move when you do the dash test.
So far a new ecu uch has been tried.
Relays and fuses have been checked we think.

Has anyone got any pointers or things to check.

Appreciate any help.

 

[JP83]

Spare clocks have been tried and they do the same. Work on the dash test, but not on ignition or engine firing up.

Tried the spare uch in a friends car and his clocks still perform as normal!?

 

[Gus]

Anyone know if there is a fuse for the needles?

 

[Stay Puft]

The fuse for those is all in one, and controls the back light of the mileage etc, and rear brake lights iirc. I blew mine when removing my cup spoiler somehow.

 

[Stay Puft]

Here you go

This sounds good.. instrument cluster I assume is speedo etc..

'F2 Stop 15A Brake lights, Instrument panel, Shift pattern control, Diagnostic socket, Driving school, Opening alert, Cruise control speed limiter control, Mobile phone connection,'

Jan 25, 2017

@optical

 

[JP83]

I've no trust run a resistor with the particular fuses but a visual check and they look ok.

That said, the instruments all work correctly when a dash test is performed so I would have thought if a fuse had gone, then it wouldn't work.

 

[Stay Puft]

I cant remember, i'm pretty sure mine worked too. It's fuse F2 so may aswell swap for a working one

 

[JP83]

Swapped f2 fuse (15amp).
Nadda

Checked the resistance on the original and it was working correctly

 

[STEVE.M]

Spare clocks have been tried and they do the same. Work on the dash test, but not on ignition or engine firing up.

Tried the spare uch in a friends car and his clocks still perform as normal!?

Logically speaking, clock test is taking power from the RH column switch.
Normal operation will be from ignition switch or ECU.?
Get back to Alex, he will probably straight on it.

 

[JP83]

So we're a bit further forward on this one.
New ecu set (with uch) means the high beam now works, and after a loose wire or 2, the horn works... :grin:

However, I still have no needle movement on the clocks.
I've put a multi meter in pins 24 (earth), and pins 4 (+ pre ignition), 16 (+ post ignition), and I get a voltage of around 12.14 - 12.19

If I try pins 20 and 22 (coolant temp indicator and + fuel level indicator respectively), I get 0 voltage.

 

[Daz...]

I think you might need to try a different set of clocks to determine whether the problem is inside them or not.

 

[JP83]

I think you might need to try a different set of clocks to determine whether the problem is inside them or not.

Have got a spare set buddy. Does the same.