1997 LX DT multiple instrument fault - please help

[AnimalMother]

Hi everyone.

I have a 406 LX DT (1997) which has an instrument panel fault. Initially I was going to change the control module, however, I think that it won't be solved by doing that.

All of the following fault are intermittent but persistent:

Eratic speedo - dropping to zero, sticking around 60mph, showing speed slower/faster than actual.

Eratic fuel gauge - showing empty, showing anywhere between empty and the actual level of fuel, moving up and down slowly.

Stop light - Stop light illuminating. This happens when the other dials are going mental.

Temp gauge - all ok.

Instrumentation illumination - sometimes on or off (only near the speedo), bashing the binacle helps.

All other car electrics are fine.

Any ideas chaps?

[Gary406]

i put money on it being dry solder joints on the circuit board on the clocks themselfs

[Gary406]

have a look on the 1st page of my picture section post .. heres link - viewtopic.php?f=20&t=16637

half way down 1st page you will see me fixing this problem not long ago. when you remove clocks you need to take off the circuit board and look for dry solder joints on the board, and resolder any thats dry .

dry joint = cracks around the solder were it solders to the board, you will need a soldering iron and solder to sort this problem

thus the reason bashing the dash helps sometimes. ps dont bash to hard or you will damage the speedo pins as i found out in my old d8.

[midsdaz]

i got the same problem with my fuel gauge its justs moves up and down but i been told there is a box behind the glove box witch controls the clocks plus i can hear it making some noise

[jonsowman]

I assume you're talking about the vehicle speed interface, which only controls the speedo/tacho I believe, though I may be wrong.

It shouldn't make any noise when it fails though... what sort of noise is it?

[Gary406]

there "may" be a box but that wont be why your clocks are playing up
my money is on dry solder joints 99.9% sure his problem is this

both my d8s had exact same faults. its just a case of inspecting the board . finding the cracks and re-soldering them

[midsdaz]

hard to explain humin noise is the best way and it only does that wen the fuel gauge is on one

[AnimalMother]

Cheers everyone, thanks for all of the ideas, offers of help and support. I'll be wielding my soldering iron this Saturday and I'll get back to you.

Cheers

[AnimalMother]

It turns out that my instrument panel isn't the same as the one shown in Gary's thread. Mine was a single PCB with everything integrated onto it. I stripped it anyway, cleaned contacts, sorted some broken bulbs, checked the ribbon cable and checked (as best I can) the cables in the dashboard. I'll take it out later to test it ad let you know how I've got on.

[Gary406]

ye there is a few different models of clusters but same applys to them all.

both my d8s had different PCB's ... but both had dry/cracked joints...

yours will be same as my old ones then. in this case . the metal clip you need to remove check this area . bend the clip so it holds tighter and clean here. if i remember rightly thats the earth point for the PCB ..

[AnimalMother]

I did that, cleaned every other contact (pins included), re-flowed the solder at some points, just in case. We'll see.

[AnimalMother]

All good.

SWMBO took the car out today. Not a hint of a problem.

Thank you everyone.

[Gary406]

it may return IF you have missed a few cracked joints. i had my clocks out 3 times before i got them all

[AnimalMother]

A few trips later and all is still good.

Let's see.

[Gary406]

well if it does turn for the worse and comes back. least you know what it is. just another dry joint somewere.

FREE fix ...