Changing a tach with a built in hour meter

[Sled600]

I have a 2004 2100SD. 5.0 liter Mercruiser. Bought it last year with non working tach and voltmeter. So... I bought a new rack of gauges (for nearly the same price as a Faria repair).

I got my replacement gauges in the mail today.... Love em... Look good, etc.
I plan to install them next weekend.

My question.....
The original tach had an hour meter. The replacement tach also has an hour meter. The hour meter function worked in the old tach..

Is it possible to attach the new tach to a battery for the same number of hours that my original tach showed? Then the new tach will show the original hours...

Obviously that would be preferred over explaining the difference to folks if I ever went to sell it....

Also,
I am not sure if the hour meter is activated by a "battery" signal or a "tach" signal...

Any ideas?

Thanx in advance!

Rocky

[mmwjr]

Hour meter is typically counting when the ignition is on and not just the battery. I don't believe there is a way to transfer the hours into the new meter other than powering it till it reached the same hour count.

[biggerseagar]

Take a very clear picture of the hours, date it, put it in your files for when you ever sell your boat. Most buyers understand all this.

Roger

[Sled600]

I did get an email back from Faria. Apparently it can be done with a square wave signal generator (whatever that is...and waiting 85.6 hours....).? I know almost as much about electronics as I do women ..so I think I will go with the picture method mentioned by biggerseagar....

Thanks guys!!!

[mmwjr]

Well that tells me the counter is counting pulses that the tach uses to display RPMs.

FYI a square wave generator is basically just that, it generate a signal that has a square shape. Start low then sharp rise to high level then back to low level. The generator allows you to set what voltage the high and low are at and the rise and fall time of the transistion between them.

As for women I have no clue, you would think i should having grown up with 4 older sisters than having 2 daughters. Only thing i learned is I give up