ah well you see theres an army of little pixies behind your dash that count how many times the speedo revoles then they convert this to mph readings
(pixies are great)

petefarrell360 wrote:Ok, I thought I remembered the speedo sensor being on the right hand front wheel, eg offside, where the dog hit, but, after consulting the old handy Haynes manual, it appears to be on the left.

It's on the left on my Volvos 300, but LHD cars...

its on the left in all cars.

Hmmmm, cheers Aymat, I'll have a look at all the possibilities poeple have mentioned, thanks guys.
Pete

Hi Pete

Glad to hear you are OK and that you`ve damaged neither yourself, the dog or the car.

re. speedos

Speedos work by rotating a magnet next to an aluminium (?) disk- no actual contact. This disc is connected to the needle and is held round at 0 by a light spring. As the rotational speed of the magnet increases it drags the disk further round.

There is actually very little force available to turn the needle - this means that any minor misalignment in the workings can cause the problems you describe. May just be a coincidence though

Check out the drive as suggested - maybe best to try and get hold of a spare speedo before taking the old one apart...

Will

Hi Will, excellent explanation there! Luckily I've got a spare speedo unit, so I should be able to drop that in at some point, I'm hoping it's something simple out of line at the wheel end of it all!
Pete

Still not had time to check the speedo thoroughly, however it is very erratic! I drove to London and back today, in total the trip was probably about 130 miles, and the speedo only worked for half of that, mainly on the way there. Started out today and it didn't work at all, then atfer stopping and switching off twice it worked the rest of the way. Then on the way home it didn't work at all, until I was about 5 miles from home, then it stopped within a mile of home again! I thought it was bump affected at first, but that doesn't seem to be the case. I'll have a proper look tomorrow.
Pete

Pete m8, you are no longer oblidged to inform the police if you hit a dog as they are no longer licenced . I still would but you dont have to

Ah, Mick mate, I had that conversation last night with my parents, about dog licencing and all! Anyway, decided it was best to report it.

How are you getting on in your new Moderator position!?!
Pete

With Hughs saying about 'bouncy' speedos, mine bounces! (seems to do it more in the hot summer days, but this could be a coincidence). Anyone have a guess as to which bit to poke? It does seem to be only below 40mph that it bounces too...

On very, very hot summer days I seem to recall the speedo bounced approximately 5 mph either way at about 45 - 50 mph. I'm probably very wrong in saying this, but I believe it is similar to a kink in the actual cable, whereby the heat temporarily causes it, at a slack point possibly? I've heard of bounces in extreme cold conditions (non Volvo), so the cable possibly freezing in an odd shape at a slack point. May be completely wrong saying that, but I seem to remember it being said somewhere!
Pete

A "bouncing" speedo is usually caused by cable problems - it`s snagging up somewhere, due to wear, corrosion or damage. Could also be temp. related as you suggest pete - expansion, contraction of parts in a cable on the way out could show up problems, as could differing viscosities of lubricants.

It is like a spring being twisted - it`s held or slowed by the snag until a certain point where the twisting force exceeds the force holding it. At this point it surges around faster than normal as the twist unwinds and your needle goes up. Once the twist is gone it slows until the twist establishes itself again and the needle goes down.

Will

5lab,
i hold my hands up im sorry you were right about the speedo i bow down in your mighty wisdom

Only domesticated animals and/or animals that are the property of someone have to be reported. Wild animals can be hit at will.....

Dogs, Horses, Cows etc must be reported to the Police.
Squirrels, Badgers, Giraffes (unless escapees from a zoo) etc do not need to be reported.

Interestingly though Deer only have to be reported in England & Wales, and Cats are classed as wild animals.

V6 Man wrote:Cats are classed as wild animals.

my gfs scottish and she's called cat. i agree wholeheartedly