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Speedo problem
sprouts-car - 27/12/13 at 10:03 AM

Morning all,

Hope everyone had a good Christmas. Back to work today so its time for LCB

Now to the problem:

My speedo doesnt read any higher than ~65-70.
I have the back of the car up in the air, put it in top gear and accelerate.
It goes smoothly from 0 up to 65 and although the engine revs higher the speedo stays at 65.

I have two magnets on the prop shaft, is it possible that at 65 the pulses are too close together and it cant read any higher?
I would have thought that if that was the case then the needle would wave around instead of sticking at 65?

Or is it something else?

All advice welcome as this fail the my IVA last time

C


snowy2 - 27/12/13 at 05:21 PM

did you buy a motorbike speedo or a "push bike" speedo the former will go to 300kph or 180mph (ish) the latter are done at about 60mph which is as fast as your able to go on a push bike......


sprouts-car - 27/12/13 at 05:33 PM

No it a car type speedo.

Looks exactly like the speedo on this page: http://www.caigauge.com/page36.html


sprouts-car - 29/12/13 at 09:42 PM

bump

Anyone got any ideas? could it be electrical interference?



c


Dingz - 29/12/13 at 10:37 PM

can you recalibrate it to work with one magnet?


Slimy38 - 29/12/13 at 10:38 PM

Can you temporarily add another magnet or two, see if it changes the point where it stops? Or maybe remove one?

If the two magnets were generating pulses too close together, eventually the signal would just blend into a single value and I'd expect speedo to start dropping back to zero.

Edit: Dingz beat me to it!

[Edited on 29/12/13 by Slimy38]