Vito 638 Instruments mystery

[StMarks]

I have a 2001 Vito 110cdi.
I was driving out of town last night, at around 40mph when my interior light came on and the instruments went out.
By "went out" I mean the rev' gauge & speedometer stopped where they were, the odometer LCD's went out, the temp gauge & fuel gauge dropped to nothing & the back lights went off etc..
The Van seems to start & runs perfectly well despite this.???

Any sage advice gratefully received please.

 

[Danny DeVito]

Maybe the plugs fell out of the back ? Only 2 screws hold it in.

 

[StMarks]

Hi DDV.
I've removed the dash (as you said, only two screws at the top & then two plugs from the harness into the instrument panel) Nothing appears untoward.? So then I & reinstalled it.

Incidentally when I unplugged the harness plugs the interior light went out, and worked correctly again from the door switches.

When I re-fitted it the interior light became permanently on again.!

 

[Marku]

Little while ago the Viano decided not to switch on the rear lights including the brakes. At least they would come on initially but then went out also some of the instruments. After much investigation by the dealer it was decided that the 'Signal Acquisition Module' was at fault. It is underneath all the electronics. Said they could run tests to make sure at a cost of £80 or go for a replacement. Took the chance that it was the SAM and everything works fine now.

 

[Danny DeVito]

Bizarre goings on. I didnt think the dash module was anything to do with interior lights. Maybe an electrical short or fault in or out of the dash is causing a problem. Try plug only one side in then try the other and see if the int light is affected. Maybe it can be narrowed down. Figure out which side and then maybe look at removing one wire at a time if ts possible. Also disconnect your battery for a few mins, maybe it will reset ? Search the fault of interior light stays on too, maybe it will turn something up

 

[StMarks]

Bizarre goings on. I didnt think the dash module was anything to do with interior lights......

The Odometer display has always come on when I have opened the drivers door, I thought that was normal ???

I presumed therefore that this was the origin of the linked symptoms.

@ Marku, thanks for your suggestion too. All my other lights/switches etc seem to be working as far as I can tell, except the warning beeper to advise that the handbrake is still on if a gear is selected.

 

[StMarks]

I have just tried a replacement speedometer cluster, and it registers nothing at all when it is connected.

So I presume that it is not my Instruments that are at fault.?

I think it must be worth me trying the SAM (Signal Acquisition Module, or Signal Register and Selection Module).

Please can someone tell me what it looks like, & where this would be located.??

 

[StMarks]

SOLVED .!!!!!

This was caused by....... ( you're not going to believe this, 'cos I didn't).... the hazard lights fuse (fuse 9 on the under steering column fuse rack) had blown.!

I hadn't used the hazzards, and I was driving at the time the instruments failed.
However fuses don't "just blow", so this is still a bit of a baffler.

Anyway, they are working again, & at least there is an answer on here if it happens to anyone else.

I shall update this post if it happens again, or if I ever discover the root cause.

 

[Danny DeVito]

Thats just crazy carry on. I reckon though that half the fuses listed dont do what they should do. Did you buy the instrument cluster ?

 

[StMarks]

........ Did you buy the instrument cluster ?

Yes DDV, I brought a fully working replacement cluster only to find I didn't need it after all.

I guess I could put it on Evilbay for £50.???