Hour meter

[dnej]

I have just been given a birthday present from my brother, an hour meter.
The instructions show connecting the positive side of the unit, to the positive wire, in a position after the ignition key.

The negative side of the meter, has to be connected before "a normally open pressure switch", I presume, they mean a start button.

My ignition has a key , that not only turns on the power, but also starts the motor.
How do these units operate.? Is it a pulse from the battery?

Are they saying , so long as it is connected to the positive on one side, and any earth wire, I would have an operating unit, which only works, when I have the key turned on.

Would I get the same result ,if I had a separate manual switch, on the positive line, that simply disconnected the positive, from the gauge,just like any other I have on a gang.

Of course I would still need to run a wire from the negative to the battery? (My ignition , is pretty chockers already)
Its an old motor, 1980 Mariner 60 hp.

I run an isolation switch, on a dual battery system, so it wouldnt get left on, so to speak.
David

[Sportfish_5]

The negative side of the meter, has to be #connected #before "a normally open pressure switch", I presume, they mean a start button.


this maybe an engine oil pressure switch which allows the hour meter to record only when engine is running.

Cheers

Greg

[dnej]

Greg, thanks for the reply. So are these gauges actually a simple, electric clock, that show the number of hours, you have the unit turned on.
I guess that is why I have seen posts, that mention hours being clocked up , because the ignition had been left on, say after flushing.
David

[NQCairns]

dnej look for a wire from the ign switch that has 12v when the engine is running ie the ignition setting like on a car.
Yeah it just counts when there is current. A better way in my opinion is to again grab your tester and find any wire under the cowl that has a constant 9 to 13v when running and 0v when not and run from there. Does yours have a light? is the power separate for it? if not the dissadvantage is the light will only work when the engine is running, this would not be not a problem to me anyway. this way you get true engine hours regardless of accidents with ignition switches etc. cheers nq

[dnej]

nq,
I thought that was the case, with current making the gauge work. This will work well, as I use an isolation switch to disconnect all power.

So if I set up the unit, (with its own warning light,) that goes off when I turn off the isolation switch, it will warn me of power on to the hour meter.
I will also use a separate on off switch, to control the power source,to the gauge, when I am using my deep cycle battery.
Many thanks
David

[dnej]

nq
No the unit is not back lit
David

[devocean]

Dnej mate of mine has got one onhis cc. His ignition key has 2 sections one turn to turn the elctrics and then a further twist to start the motor. I accidently left it on one day after a flush he wasnt happy because alythough the motor wasnt going the hour meter still turned over.

[dnej]

Devocean,
Thats how my ignition works.
Thanks for that, I have heard that it happens quite regularly.
I think I will wire it separately, with a warning light .
David

[Willdoe]

David
Yes they are appear to be only clocks that run when the ignition is on. I have learnt the hard way with over 100 hrs up on my 2003 model Merc but only about 40 genuine hrs due to the ignition being left on while the boat was on the trailer. I now have the key on a cord and try to remember to pull it out when out of the water

I would be interested if anyone knows if you reverse the polarity would they run backwards to correct the error. I'm concerned there may be a pawl like on a trailer winch that prevents reversal. I don't want to burn the meter out.

Willdoe. :) ;)

[Spaniard_King]

David
Yes they are appear to be only clocks that run when the ignition is on. I have learnt the hard way with over 100 hrs up on my 2003 model Merc but only about 40 genuine hrs due to the ignition being left on while the boat was on the trailer. #I now have the key on a cord and try to remember to pull it out when out of the water

I would be interested if anyone knows if you reverse the polarity would they run backwards to correct the error. I'm concerned there may be a pawl like on a trailer winch that prevents reversal. I don't want to burn the meter out.

Willdoe. :) ;)

reverse polarity will not change the hour meter back...I have tried it too :( you have 2 options...are you using it to log hours for engine service ??? or are you thinking of resale value.. I am using mine for engine hour service so when the key was left on I just left it on until I new that it was 100hours ahaed of the original time. the new hour meter will go in befor I sell the boat, guess i will just leave the key on again till the meter is up to the correct time :o

Garry