calibrating smiths/cearbont/revotec speedometer

[Comadis]

i´m struggling calibrating my (modern)smiths electronic speedo.

4 pick-up sensors on propshaft.

the problem is: it works but reads too high as i cant change the factory setting

according to the manual the calibtaring mode is selected by switching on ignition while simultaniuosly holding the programming button and waiting for 3 seconds.

but even when i push this button longer than 3seconds nothing happens. the display shows the mileage or the trip and i do not reach the programming mode.

i pressume with "programing button" is meant the little rubber button on front of the speedo which you use for resetting the trip, or is there another button somewhere else?

and no, its not the "older" dip-switch type.


during my web-search for the calibration manual i found certain threads about problems with these gauges in cobra forums, so it seems that i´m not the only one.

the (new) speedo was fitted 2008 by the former car-owner, so it wasnt my choice. when i purchased the car in 2009 the speedo showded 75miles, so its pratically new. i drove it the summer season with keeping in mind to sort out the wrong reading during the winter period.

any idea´s?

Edited by Comadis on Wednesday 27th January 11:29

[simon3000]

if it is anything like my atb unit you could try turning the ignition off then on whilst holding in the function button.

[rdodger]

simon3000 said:

if it is anything like my atb unit you could try turning the ignition off then on whilst holding in the function button.

Same for Smiths/ Caerbont

[Comadis]

already tried..no chance.

in another manual it says:

hold the button, switch on ignition and release the button after pressed min. 3s-->no chance.


here is the manual:

http://www.caigauge.com/page28.html

and a similar manual (which imo explains it much easier):

http://www.toyne.org.uk/docs-speedo.html


and it does not say anything about turning OFF the ignition!!


1.Press front mounted button and keep pressed
2.Apply 12 volts to instrument (via ignition)
3.The display will loop through AUtOCL, PULSE and AdJUSt at two second intervals

i never reach no.3

Edited by Comadis on Tuesday 26th January 19:03

[russell_ram]

On mine (2004 Smith elec), the 'calibration' button is on a flylead that is part of the multiplug on the rear of the speedo. The button on the front only does the trip/accumaldated display change.

[Comadis]

hi russell, good advice..i will check it this afternoon and will report!!

do you know if these instruments, when purchased new, come with a pictured manual which shows where such buttons are located?

if yes, could anybody scan the pages, or take a digital picture and posting it online?

[russell_ram]

Well I'm sure it came with some instructions but it'd be a challenge to find mine - I've moved house since I installed it. I can have a quick search for you later if no-one else comes up trumps.

Russ

[Comadis]

who said "and no, its not the "older" dip-switch type."

was it me?

its the dip-switch type!!!

but thanx again to russell!!! without your advice i wouldnt have removed the speedo out of the dash and therefore wouldnt have recognized the large rubber grommet which covers the dip-switches!!!

[speed8]

Did you fix it yet? I only ask because even some of the later digital Smiths speedos still have dip switches to tell it what sort on input, and hence, what wires the input will come in on.

I set mine up a few months ago and you do just press the button, turn on the 12V, wait a few seconds till the display flashes the follow the instructions from there on how to input the number.