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        General >> Problems >> speedo works/works not
        
(Message started by: ghia-cossie on Nov 11^th, 2007, 9:44pm)

Title: speedo works/works not
Post by ghia-cossie on Nov 11^th, 2007, 9:44pm

to make al long story of my other topic shorter i desided to make an new threat.

my wiring loom is completly new, vss is tested en ok.

but yesterday my speedo was working, today it isnt, al speed related functions dont work.

is there something in the car that distributes the vss signal or is it just as in the loom itself just spliced up to different modules and the dash?

could be a faulty connection in the bulhead connector but i cleaned that one several times.

greetz

Title: Re: speedo works/works not
Post by Havinga on Nov 11^th, 2007, 10:25pm

Have a look at the pdf's here. http://www.carsoft.ru/avtorepair/sierra_el.html
Ignore the fact it has sierra in the address.

Title: Re: speedo works/works not
Post by ghia-cossie on Nov 11^th, 2007, 10:55pm

i am so desperate, the drives so great when it works but in this condition it drives me mad, i thought of breaking it and shovel the engine in my sierra.

i cheked al the wiringdiagrams to find the splices of the vss signal, if im right theres 1 at the radio and i instaled an non original one from jvc maybe i shorted a wire.

im sorry for the different topics but i dont know it anymore.

it stops working and suddenly without doing anything to it it works , an day later ik drive it and everything is dead again, but the engine runs perfect and the box shifts smooth, no cruisecontrol no tripcounter.

when i pull of the battery leads, en put it back again the instrument cluster cheks itself so thats a sign it cant be broken.

if there is no vss signal the box should shift rough and thumpy, and the o/d light flashes.

the wiring loom is 100% ok, tomorow i will chek al the connectors, chek the instrument cluster, and al the wires behind the dash.

i cant get it over my hart to break it, poor me.
they call it a hobby, i call it a disseas.

greetz

Title: Re: speedo works/works not
Post by Havinga on Nov 11^th, 2007, 11:52pm

you've got a bad connection somewhere, i would start with the vss itself, it's a pain to get at, but if you can take it out and check it's sill got all of it's 21 teeth? then check that the loom from the vss back to the box hasn't chaffed any place, pay attention to where the loom comes close to the shift rod, check it doesn't snag when in drive.
Lastly disconnect the vss input from your radio, press and hold the mileage reset for 5 secs to enter the clockset into diagnostic and cycle through to the speed bit.
more details are on this site somewhere but i've forgotten under which heading.

Title: Re: speedo works/works not
Post by Simmo on Nov 12^th, 2007, 9:04am

I think THIS (http://www.fordscorpio.co.uk/instreset.htm) is what you are referring to. ;)

Title: Re: speedo works/works not
Post by ghia-cossie on Nov 12^th, 2007, 10:34am

intresting, but is that the reason for other things failing such as the cruise control tripcounter.

wiring loom is completely new and i tested al the connections when it was on the car , it turns out that everything was ok.

greetz

Title: Re: speedo works/works not
Post by ghia-cossie on Nov 12^th, 2007, 11:23am

just did the instrument test:

the 2 displays showing al digits and pressing the button i scrolled trough the parameters, speed shows nothing when driving all others seems te be fine.

the manual on this site says al lights should light up and the needles must flip, mine doesnt.

i disconnected the battery to reset everything and i will try the car after i had some breakfast.

the radio wiring not contains the vss signal i think its because my car is equiped with a standard stereo type radio , so it cant be wrong out there.

i really begin to hate this car, but still love her and want to make it better :(

i also found out that if the speedo is working, the cruise control only works when pushing the RESUME/CANCEL button, ond not with on or of.

greetz

Title: Re: speedo works/works not
Post by jonnycab on Nov 12^th, 2007, 11:28am

There is a VSS signal at the radio because my taxi meter is wired into it for the pulses. My old Scorpio with the old type radio also had the meter wired up in the same way :)

Hope this helps :)

Title: Re: speedo works/works not
Post by ghia-cossie on Nov 12^th, 2007, 11:42am

according to the wiring diagrams it must be white/green wire, but i cant find it in the radio wiring.

Title: Re: speedo works/works not
Post by ghia-cossie on Nov 12^th, 2007, 4:22pm

can anyone confirm if this is right:

wires in the loom for vss:

white/blue - vss signal (puls)
black - vss ground
purple - vss power

wires out of the vss itself:

yellow - pulse
black - power
brown - ground

so i have to connect as follow:

purple to black
white/blue to yellow
brown to black

greetz

Title: Re: speedo works/works not
Post by Snoopy on Nov 12^th, 2007, 6:05pm

The way I understand Fords wiring is that BLACK is always used as earth and NOT a live feed so in your explanation
Quote:

wires out of the vss itself:

yellow - pulse
black - power
brown - ground

I think is wrong but others may have MORE knowledge that me on this one .
I have checked MY copy of the wiring diagrams and BLACK IS ground .

Title: Re: speedo works/works not
Post by ghia-cossie on Nov 12^th, 2007, 6:39pm

i cheked it with the old loom:

black = ground
white/blue = pulse signal
purple = power

the purple wire goes to the dataconnector of the gearbox and is shared with 3 purple black wires that provide the solenoid power, after the sharing point the wire becomes purple/blue en goed to the bulkhead connector on the left side of the engine ( lhd car)

so indeed this is the right way of connecting the wires:

so the purple wire goes to the black one of the vss
the wite/blue wire goed to the yellow wire of the vss
and the black wire goed to the brown wire of the vss

i am glad that there are people that give me serious tips, forums in holland suck, they always go offtopic and come up with stupid ideas.

thanx alot all of you!!!

greetz

Title: Re: speedo works/works not
Post by harry.m1byt on Nov 12^th, 2007, 9:17pm

One certain method to check for the pulse would be with an oscilloscope - rather expensive, but there you are.

Another method would be to try a logic probe which is switchable to CMOS input levels. Basically you connect it to a 12v supply and connect the probe tip to the cable in question. Three LED's indicate a positive, a negative - the third flashing (and a tone) if there is a pulsing signal appearing on the wire between certain voltage limits. As indicated this would not be certain to work, as the pulses have to meet a certain criteria.

From memory the criteria being the pulse voltage has to rise above 70% of the supply voltage and fall below 30%. I would guess the VSS signal would almost certainly meet this criteria.

The TTL level setting of the probe is designed for 5v logic levels and may be damaged by the 12v.

Title: Re: speedo works/works not
Post by ghia-cossie on Nov 12^th, 2007, 10:18pm

vss is ok, tested with leds, and tested the other from the sierra wich does exactly the same as the one from the scorpio so i think its ok.

tomorow i make a bypass cable from the vss directly tot the wires it needs in the bulkhead connector, if its still fail to work its something else and if its working the solution is that bypass.

so i keep you guys updated.

greetz

Title: Re: speedo works/works not
Post by ghia-cossie on Nov 13^th, 2007, 2:48pm

i thought i solved the problem, but i didnt.

made a bypass with the vss wires, hooked it up in the connectors, and speedo works, so i went for a drive.

cruise control worked but only by pressing + it turns on and i could only control it by pressing + and -, turning it op worked with the on/of buttons.

speedo still worked during the drive but o/d flashes, so i turned of the car and started it again, and what happend, no speedo no cruise etc. etc. car sometimes shifts up and in eco it revs till 6000 and finaly shifts, shifts are not rough.

cheked the pulse wire from the eec and it has a constant ground.

so if someone has an idea share it with me because breaking the car is my only way out at this moment.

Title: Re: speedo works/works not
Post by Snoopy on Nov 13^th, 2007, 3:57pm

The cruise control is supposed to work the way you state .... press the white button toturn it ON and then use the + to set and the - button to reduce speed ... the = button resumes AFTER pressing the brake or clutch.... it does seem that the wiring is at fault and I would have thought the small loom from the gearbox is the one that needs to be replaced/repaired .

Title: Re: speedo works/works not
Post by ghia-cossie on Nov 13^th, 2007, 4:14pm

gearbox loom is new, and tested with an original one and wired up correctly.

but is it right that the blue/white wire in de c113 bulkhead connector gives a constant ground with key on
and the connectors fro mthe engine/gearbox removed.

i have now al the dashboard parts out to look after the wiring there, going to disconect the cruise module ect, to find the problem.

with another loom or a bypass it still refuses to work.

Title: Re: speedo works/works not
Post by Snoopy on Nov 13^th, 2007, 7:29pm

IS the relay faulty?

Title: Re: speedo works/works not
Post by ghia-cossie on Nov 13^th, 2007, 9:38pm

wich relay and where to find, i think you mean the relay under the dash at the passengers side of the car? in the glove compartiment.

is that a common fault?, at least it makes sense that this could be the problem.

i never had a problem like this, not even with more complicated car electronics.

a speedo just works or not works, this is working and working not and without doing anything to it it works after not working.

so i conclude that the wiring is ok cause it works as it is now, but fails and working again, can you guys get it , i dont.

greetz

Title: Re: speedo works/works not
Post by Snoopy on Nov 14^th, 2007, 7:42am

Going back to the start.
I know you state the VSS "checks " out OK but as that is the one part of this equation which is an unknown quantity. You appear to have an intermitant fault . Perhaps you could obtain a known second hand one .
Particularilly as you have had your speed working ( if only for a short time ) . I would go back to basiscs and start there . The relay to look for is NO 37 behind the glove box a Green one which is on the speed conrtrol circuit .

Title: Re: speedo works/works not
Post by ghia-cossie on Nov 14^th, 2007, 9:55am

scorpio 95+ parts are difficult to obtain, a new one set me back 150+ euro.

i tried a vss from the mt75 gearbox, pluged the wire is the socket and turn it by hand, but there was no pulse and that vss is from my sierra wich works excelent.

so if there is no pulse, and there is a constant ground on the pulse wire from de female connector on the bulkhead it seems to me something else is wrong.

i dont ignore your answers but its complicated to explain.

greetz

Title: Re: speedo works/works not
Post by harry.m1byt on Nov 14^th, 2007, 9:27pm

I think you have arrived at the conclusion that the VSS is fine, is generating the pulse, but that its pulse output at times is being grounded by something on the VSS circuit.

Your solution seems to be to check everything on the VSS's output for a fault. From memory the VSS signal goes to the speedo, the cruise control and the ECU. So either one of those is pulling the signal down or there is a fault on the wiring. Obviously you can quickly and easily unplug the cruise control module without any ill effects to eliminate that from the equation. It's the little black box in the tray just above your right knee.

Title: Re: speedo works/works not
Post by ghia-cossie on Nov 14^th, 2007, 10:34pm

its a LHD car, so i have to unplug the blackbox under the steering wheel, i have seen that thing indeed.

im still looking in the wiring diagrams in TIS but its not clear to me what happens with the speedpulse wire( white/blue) after it dissapears into connector c113.
is it splitted up or is it going from module to module?

one thing is for sure, my sierra with the old 12v v6 from a scorpio is a hell of a lot hufter proof than this scorpio, when i want that sierra to die i have to throw it of a skyscraper :P the scorpio just quits when you look at it ;D

little fun at the time keeps you sharp en laughing 8)

greetz

Title: Re: speedo works/works not
Post by ghia-cossie on Nov 15^th, 2007, 9:40pm

someone who knows what the brown/white wire does at pin 9 of the 470c connector at the instrument cluster?

according tot tis its a sensor signal return , and in the wiring diagram it goed tot the instrument control module.

is the instrument control module a thing that can cause this problems?

dont have the car at home so i cant quikly try al these things you guys suppose.

im making a list of possibly causes so when i have the time to chek it out i have multiple things to try to fill a day ;D

greetz

Title: Re: speedo works/works not
Post by Havinga on Nov 15^th, 2007, 11:27pm

From what i can see on Tis, pin 22 on 470c is bn/wh and goes to pin 1 on c523,(instrument cluster mode switch)
pin 9 of 470c is bk/rd and goes to pin 19 on c551 central timer & c200 pin 10.
Pin 26 on c470b is wh/gn Speed sensor that intern goes to C446 pin7 (shorting bar)
an becomes wh/rd, that goes off to the pcm, power steering module and back to the speed sensor itself as wh/bl.
the other side of the shorting bar C446 the speed signal goes to the radio, speed control and (SATC) air con. 8)

Title: Re: speedo works/works not
Post by ghia-cossie on Nov 17^th, 2007, 4:19pm

turns oput to be a faulty vss ??? >:( :-[ :-X :-/ :'(

anyone who knows the 1994 cosworth autobox vss is the same a the 1995 autobox cosworth?

i hope so :)

greetz

Title: Re: speedo works/works not
Post by Snoopy on Nov 17^th, 2007, 4:35pm

Think it is.

Worth a try if you have one

Title: Re: speedo works/works not
Post by ghia-cossie on Nov 17^th, 2007, 4:41pm

i can buy one for 20euros, thats nothing.

new it costs over 200, they told me at the ford dealer.

but i want to be realy sure they are the same, because i can buy more of them at once, just in case ;D

groeten