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Topic: Mondeo speedo problem (Read 190 times) |
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Jonnycab
Senior Member
Former owner of 2.3 Ultima Facelift saloon
Posts: 3900
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Mondeo speedo problem
« on: Aug 12th, 2010, 4:14am » |
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Just wondered if there were any MK3 Mondeo techie/knowledgeable folk here ?....as a mate of mine (fellow cabbie) has a 53 reg 2.0 diesel Auto Mondeo with a speedo problem.
Intermittently the speedo will stop working & the digital odometer will read just lines where the digits should be....& at the same time the taxi meter will stop clocking up the fare (good for the punter eh  )
His local mechanic that he has used for a few years & so trusts him, has diagnosed a bad 'speedo head' & quoted a bill of £400 for a new dash from Ford  ....plus £30 labour to fit.
But I'm not convinced the mechanic's diagnosis is correct & have told my mate that it sounds more like a VSS problem, mainly due to the fact that the taxi meter is spliced into & takes a pulse from a wire at the back of the radio (like most taxi meters are)....hence a bad dash shouldn't affect the running of the meter.....or would it ?.....does this pulse wire run from the dash ? 
Any thoughts or theories ? 
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Simmo
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I'm an OAP !
Posts: 5508
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Re: Mondeo speedo problem
« Reply #1 on: Aug 12th, 2010, 5:33am » |
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Jon, I put 'Mondeo Speedo Problem' into Google and there are numerous links...BUT...there seems to be a common thread about the VSS which apparently is hard to find but either on top of or on the side of the gearbox. There is also a mention of the fuel warning light coming on at the same time?. HTH
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Tompion
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1997 2.3 Ultima estate.
Posts: 2918
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Re: Mondeo speedo problem
« Reply #2 on: Aug 12th, 2010, 11:13am » |
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Could be the other way round - when the taxi meter stops clocking up the fare the speedo stops working. It might be worth re-making the meter splices or disconnecting it from the radio wire.
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ABS multiplug wheel sensor pins MK IV or MK 20
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Jonnycab
Senior Member
Former owner of 2.3 Ultima Facelift saloon
Posts: 3900
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Re: Mondeo speedo problem
« Reply #3 on: Aug 13th, 2010, 1:31am » |
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Mike, I read the same when googling it, although VSS problems seemed to be more common in the MK2 Mondeo. Also read about the fuel warning light coming on when it's a problem with the dash (dry solder joints etc), but my friend doesn't have this .....have also read that a VSS problem can turn on the 'Check Engine Light', but he doesn't have this either
I did plug my handheld scanner in & it came up with 'no codes'. But this is no surprise, as it tends to only display engine fault codes
Dave, good thought....I'll ask him if the speedo drops when the meter isn't on....although I'm not sure that this could be a cause
I've never fitted a taxi meter before, but as far as I know the wire behind the radio that the meter takes it's pulse from is the wire that comes from the VSS & provides the radio with speed sensitive volume.....I just need to find out if this signal comes from the dash or it is split before it reaches the dash
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tlundkvi
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Ex. Scorpio 2.9 24V -95
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Re: Mondeo speedo problem
« Reply #4 on: Aug 13th, 2010, 10:13am » |
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My VSS's bearings gave up at 178000km, and I believe the mondeo VSS has similar construction. It worked when engine was cool, stopped working once it got hot. I think the gearbox has another set of codes read a special way as e.g. ABS codes, I recall getting no codes either.
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Highlander
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Expert
13 Scorpios, XR4x4, Suzuki SJ413 for off road :)
Posts: 8244
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Re: Mondeo speedo problem
« Reply #5 on: Aug 13th, 2010, 2:35pm » |
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"Intermittently the speedo will stop working & the digital odometer will read just lines where the digits should be....& at the same time the taxi meter will stop clocking up the far"
No experience of Mondeos but using Scorpio logic I would doubt a dodgy VSS would do that to the odometer...
As you say the speedo reading shouldnt stop the meter so... must be the wiring! EASY 
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on Oct 17th, 2011, 12:35pm, Simmo wrote:I give up !  Too much for an old boy!  |
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Mike H
Senior Member
Renault Clio
Posts: 2594
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Re: Mondeo speedo problem
« Reply #6 on: Aug 13th, 2010, 3:24pm » |
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on Aug 13th, 2010, 2:35pm, Highlander wrote:but using Scorpio logic I would doubt a dodgy VSS would do that to the odometer...
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I thought that actually
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Mike H
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Jonnycab
Senior Member
Former owner of 2.3 Ultima Facelift saloon
Posts: 3900
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Re: Mondeo speedo problem
« Reply #7 on: Aug 15th, 2010, 2:12am » |
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Well......my friend didn't take my advice to get a second opinion from an auto electrician & went ahead & had the garage put a new dash in on Friday
Total price came to over £500 inc VAT.....& what happened when he got half a mile up the road ?....yep, you guessed it, the speedo stopped working, the odometer just read lines & the meter stopped totting up.....so nothing's changed apart from his bank balance.....some people never listen
It's now back in the garage again for the weekend while they try to figure out what is really wrong with it.
......ooh, the suspense is killing me
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Jonnycab
Senior Member
Former owner of 2.3 Ultima Facelift saloon
Posts: 3900
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Re: Mondeo speedo problem
« Reply #8 on: Aug 15th, 2010, 2:32am » |
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Heads up !! ....just found THIS
Exact same problem on a 52reg TD Mondeo & if you read the second from last post, it says it was diagnosed as a faulty VSS
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Jonnycab
Senior Member
Former owner of 2.3 Ultima Facelift saloon
Posts: 3900
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Re: Mondeo speedo problem
« Reply #9 on: Aug 21st, 2010, 3:13am » |
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Problem solved.....the original garage gave up on trying to fix it & told my friend to take it to Ford.
So he booked it in at the local FMD, where they diagnosed it as a faulty VSS. So in goes a new VSS & what do you know ?....it didn't solve the problem
After much head scratching, FMD stuck a new battery in it & voila!!!....the fault was cured
Now, what confuses me , is that there was no evidence of a battery fault when starting the car & the fault would only occur while the vehicle was in motion. There was no battery/alternator light illuminated, not even faintly & no DTCs were detected when plugging in my handheld scanner.
Seems that maybe applying Scorpio logic to the MK3 Mondeo doesn't work......or maybe (more likely) FMD are fibbing & it was actually just a loose earth wire & they just fancied selling him a new battery just to bump up the cost ?
P.S...my friend is currently trying to get his money back from the original garage & has so far got the cost of the new dash back, but they are refusing to reimburse him on any labour costs
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