KAD 44 EDC how to advance the engine hours displayed

[simonfraser]

Just changed the LCD, now showing the wrong engine hours
I need to advance the hours by about 300 to get to the correct amount

Is there some way to wire the tacho up and advance the hours without running the engine ?

 

[julians]

I dont know a sure fire way, but I bet its just a matter of sending a pulse of the correct voltage down the correct wire a few hundred thousand times.

So you'd need some way of generating that pulse , maybe a 555 timer chip could be used to do it.

 

[Momac]

Will connecting it to 12 volts for the required time not do the job?

 

[julians]

Im guessing just connecting to 12v wont work, im guessing the tacho only advances the hour meter when it thinks the engine is running ie turning over at greater than zero rpm, so to simulate this youll need to send a pulse down the right wire to simulate the pulse received from the alternator. The tacho should then show x rpm on the dial and advance the hour meter for the duration it is fed with a signal

I could be wrong though, this is only an educated guess.

 

[simonfraser]

any one got a wiring diagram for the tacho ?

the blue/red is likely the live feed according to some threads

 

[spannerman]

I am pretty sure it will advance if you just give it 12v on the blue/red and black to minus. The pulse on the grey just activates the rpm function.

 

[simonfraser]

I am pretty sure it will advance if you just give it 12v on the blue/red and black to minus. The pulse on the grey just activates the rpm function.

grand

 

[petem]

Easy to establish, jut try it for 6 minutes.

 

[simonfraser]

yep, just wanted to make sure about the polarity / wire colors

 

[aquatom]

Just connecting power to it won’t start it counting. It needs a pulse or an ac signal. I would think a 50hz signal from a phone charger would do it but not tried that!

 

[julians]

Just connecting power to it won’t start it counting. It needs a pulse or an ac signal. I would think a 50hz signal from a phone charger would do it but not tried that!

Phone charger output will be dc(and therefore no pulse) i would have thought.

Or are you thinking that they will use a cheap rectifier circuit that whilst outputting dc will still result in dc pulses?

 

[simonfraser]

Just in case any one else looks at this, yep just leaving the ignition on does not advance the hours run.
Gota run the engine, guess it needs a pulse from the rev counter.

 

[Grubble]

In that case, something like this will probably do what you need:-

https://www.ebay.co.uk/itm/PWM-Puls...ule-Square-Wave-Signal-Generator/272894009901

Check the rev counter pulse with a voltmeter first to see what range it is in.

 

[simonfraser]

Tnx, crack in the exhaust bellow just now, that will have to be sorted first.
Recon the hour meter will be a great winter project

 

[magichands]

I know a chap that has a rig to do this. He charged me £30 per gauge to do mine. I will try and dig up his email address.

 

[simonfraser]

tnx pm me just in case i dont look at this thread.