General Siecento Speedometer Wonky

[Kestrel]

Hello,
my speedometer is haywire, i have tried opening up the pod and resetting it several times, but when i start the engine up it immed gos wonky
before i even drive anywhere, please help as it is not safe as is....
It is a 2001 Sieecento 1.1 mpi
with the small pod with no speedo cable, but two multiplugs in the back of the pod...
thanks,
Paul
:bang::bang::bang:
:bang::bang:
:bang:

 

[fingers99]

There's a speed sensor on the back of the gearbox/differential which the speedo (and. much, much more important) the power steering takes its signal from. Clean up the contacts, check the wiring.

 

[rallycinq]

If its bouncing around as your starting the car its an engine earth problem.

The starter is trying to earth through anything it can find and the speedo sensor wiring is in the firing line.

Remove, clean and refit engine earth.

Cheers

SPD

 

[Kestrel]

Thankyou guys...
I am going to have a look now...
I just wonder ~ i fitted an extra earth
the other week from negative on battery to
chassis, is this a bad idea ? I thought this was a good idea ?
Does the speedo pod earth thru the two allen bolts that mount it to the column surround ? I wouldnt have thought so..
This issue is grinding me down a bit, btw i
seem to have sorted the LED half~display issue, the big multiplug in the back of the pod did not seem to be seating fully, so i carefully inserted a small screw part way down the side (which is not contacting any metal btw, and the speedo issue was there b4 and afta this mod)
So, as it happens, the earth issue is something i have dealt with extensively on Fords:bang: and have counselled many to fit extra earth (s), which is free and a great idea... I am starting to wonder if fitting the earth was s]a good idea, where is the earth strap ?
Thanks

 

[Dan]

Adding another earth is fine as long as you clean the contacts before you put them back and then grease them to stop oxidattion.

Strap is from top of gearbox to the passenger side arch near the ECU.

 

[Kestrel]

You know, you guys here are the tops you really are..
As a member of rs2000-16v.com where i spend a fair amount of time evry day helping others and learning myself ~ i was expecting a cold reception here, i didn't think it possible to be fortunate enough to own two cars with exceedingly helpful fellow~owners...
But I am, so a Big Thankyou to the above poster, SPD, Kris, and Fingers, and others (you know who you are)

 

[Kestrel]

I am going down now to check/sort the above described earth and see how it is after, also
to remove/clean the speedo thing atop
the g/box, thanks

 

[Kestrel]

Just been down and removed the extra earth just in case (in some quirky~way) it was bad...
Anyhow, after checking the lil multi atop the g/box (wires seem okay)
Unplugging and spraying some WD in there and
reconnecting ~ still the same...
Remember folks, i have fitted a new power steering electric pump...
Is there some kinda reset thing somewhere ?
I have just checked all fuses too, incl big 'uns behind batt

STUMPED

:bang::bang::bang:
:bang::bang:
:bang:

 

[signwerx]

Try conencting a jump lead between the battery negative and something solid on the gearbox. (Like the gearbox side of the front gearbox mount.

This will at least isolate whether you have a bad earth between engine and body.

Secondly, if the above fails.

I would buy a new sensor from fiat. If you have fitted new power steering stuff, you may have squashed or nicked the cable.

Hope it helps

adam

 

[Kestrel]

Try conencting a jump lead between the battery negative and something solid on the gearbox. (Like the gearbox side of the front gearbox mount.

This will at least isolate whether you have a bad earth between engine and body.

Secondly, if the above fails.

I would buy a new sensor from fiat. If you have fitted new power steering stuff, you may have squashed or nicked the cable.

Hope it helps

adam

Hey there,
That sounds like a plan ~ I will go down in a mo and do the
Jump lead Earth thing...
But, without dissing what you r saying, if I get a new sensor (i take it you mean the one into the gearbox) how would that sort a squashed/nicked cable ?
Paul

 

[Kestrel]

Could there be a Reset button on the ecu for the power steering,
I recall they have a seperate ecu for the powa~ste ?
I will try the earth thing, but i am wondering if it is
a compatibility issue, i only fitted the electric pump,
Not the upper steering column, altho i have that...
Thanks

 

[rallycinq]

The earth that you put in will do no harm, but it would be better between the engine/transmission and the battery/chassis.

Using the single jump lead to check the requirement

Cheers

SPD

 

[randomizered]

Unplug the VSS at the rear of the gearbox. 4? wires. If it's unplugged, does it still go crazy?

 

[Kestrel]

Hey,
I have been and removed the original earth g/box~chassis and
glasspapered it, replaced the bolt into wing, greased it...
Also did the Batt Neg to a bit of g/box that i angle~ground...
And ~ Nothing, still the same...
I am at a loss with it...
Do you think i should open up the pod (for the tenth time)
and wind it back a dozen times or something /
I suppose that wouldnt change it...
So, no~one knows :bang: :bang: :bang: :bang:

Thanks tho all

 

[Kestrel]

Unplug the VSS at the rear of the gearbox. 4? wires. If it's unplugged, does it still go crazy?

I will try this tomorrow Kristian,
And get back here
Thanks...

 

[Kestrel]

BTW just in case anyone thinks i am obsessive at recording detail, i've discovered that one day (poss several times already) many peeps will
be searching posts like this before posting a new thread, so this is
an attempt to help you mr. future guy/gal !

Now, I have just spoke to fiat (v.friendly man, he owns the whole show)
He says there is a wire that corrodes behind N/S h/light that causes this..
So, I am off to do what Kristian says, try n see if it happens when the vss(vehicle speed sensor) removed ? unsure how this will affect issues
for a coupla reasons, BUT he is a whizz with these cars, as is fingers and
RallyCinq

Another small Issue I want to record for Posterity ~
The Problem with poorly displayed LED mileage etc (flickering)
Was solved by the CAREFUL insertion of a small screw down the side of where the multiplug gos into the back of the Pod....
It is fine now,and mr fiat garage 1975 tells me this is a known Cure..
But be careful and gentle, and DO NOT contact any connections, or break the plastic, it has to be very small...
Paul

 

[Kestrel]

Latest ~
I have here (in~house) the foot long harness that has the three multi's on it,
the central one being the VSS atop the g/box...
It has a multi on either end and the VSS in middle, so is
Simple to remove...
I have fully tested it and it is Fine...
Also in repsonse to Kritip's sugg. I removed the plug from the
VSS ~ and I can report back that it still does it...
:bang::bang:
:bang: