How to connect an hourmeter to the alternator

[cmedsailor]

Unfortunately my "electrician knowledge" is almost zero, so could someone explain me as simply as possible how to connect the two wires of an external hourmeter to the alternator of a Volvo Penta 2030D.
Thanks

 

[bendyone]

It shold not be connecter to the alt. but connect the -ve to the earth system and the +ve to the switched side of the ing. switch. So it will be powered only when the ing. switch is on.

 

[alanwilson]

Why connect an hourmeter to an alternator? The only hourmeters I've come across are simply a clock which runs when 12v is connected, so you connect their -ve to the -ve bus (the common -ve to the battery) and the +ve to the key switch for the engine. The first key switch click turns the engine electrics on, then hold the switch against the spring to turn the starter on, then release back to the first click & let the engine run.

So with a voltmeter, find what contact on the key switch is made live (+12v) when the switch is turned to the first click: connect that contact to the +ve on the hourmeter.

OK, the meter will then measure the time that the key is turned on, not the time the engine is actually running, but you don't leave the key on with the engine stopped, do you! And much simpler, especially when you need to change the alternator.

Just in case sucking eggs is not your thing:
set your voltmeter on Volts, DC, 20 (get help if needed!)
connect the -ve wire to the -ve on the battery
turn the key switch one click to turn the engine electrics on
touch the voltmeter +ve wire to each key switch contact in turn
note which one(s) show 12v or thereabouts
turn the key switch off
note which of those contacts now show 0v
repeat to identify definitely a contact which is 0v when the switch is off and 12v ish when the switch is on
remove the voltmeter
connect the hourmeter -ve to the battery -ve
connect the hourmeter +ve to the identified contact
turn the key switch off, leave for 5 min and check the hourmeter shows no gain in time
turn the key switch on, leave for 5 min and check the hourmeter shows 5 min gained
wire the hourmeter in permanently, to the nearest common -ve and that contact on the key switch.

Easy!

 

[cmedsailor]

Sorry, maybe I have confused the words as English is not my official language. I would like to connect the hourmeter to the AC generator (I am not sure if it is the same as the "alternator"). I guess the AC generator works only when the engine is on, thus will count engine hours. Plus the place is very convenient for placing the hourmeter.
Thanks

 

[Travelmate]

Early Volvo hourmeters connected to the centre tap of the alternator and used pulses to drive the meter.
Another way of connecting the latest hour meter is by a double contact NO oil pressure switch. This ensures the hour meter will work only when the engine is running (has oil pressure)

 

[VicS]

Alan Wilson

why not consult the wiring diagram in the owners manual then you can tell cmedsailor exactly where to connect the hour meter without all this messing about with voltmeters.

 

[VicS]

No it will not work just connected to the alternator output because that is connected to the battery all the time the battery isolator is closed. A simple hour meter just runs while it is connected to 12 volts.

Assuming this is the type of hour meter you have.

There are three different types of instrument panel for the 2030 engines.
One does not have a key type ignition switch, just a panel on off switch and a separate starter button and glow-plug/alarm test switch.

The second has a key type ignition and starter switch and an alarm test button

The third has a key switch and alarm test button and also has a voltmeter, an oil pressure gauge and a temperature gauge.


Irrespective of the type, you will find a red / blue wire, or wires, running from the ignition switch, or in the first type from the panel switch, to the electronic module the rev counter, the panel light switch and the additional gauges where fitted

This red & blue wire is the place to make the positive connection for the hour meter.

The negative should be connected to one of the plain black wires which run from the 16 pin connector to the electronic module, the rev counter the additional gauges and all the illumination bulbs.

The most convenient place to connect may be to the red & blue wire and the black wire at the rev counter or the electronic module but it is your choice.

You should if try to include a fuse in the positive connection. Just large enough in value to supply the hour counter.

I hope this helps. Refer to the wiring diagram in the owners manual and if in any doubt get help from someone who understands wiring and wiring diagrams

 

[cmedsailor]

Guys thank you. I'll just call an electrician to do the thing (I know it's simple but not for me).

 

[rogerthebodger]

Depending on the voltage required to drive the hourmeter it could be driven off the tachometer output for the alternator and depending on if the hour meter needs AC or DC would indicate is a bridge rectiier is needed.

I will be doing a simular set on my new yacht.

 

[VicS]

[ QUOTE ]
I will be doing a simular set on my new yacht.

[/ QUOTE ] The thing is you know what you are doing, you know about the ouput from the alternator.

In fact the tacho on the 2030 etc engines gets its signal from the W terminal on the alternator. The optional hour meter, which actaully is part of the tacho when fitted, is fed in the way I have described, from the switched +ve that supplies every thing in the panel. (well from the negative and positve connections to the tacho)

 

[Blue5]

I sympathise with you, I asked the same question about six months ago.

I bought an hour meter with the idea of connecting to the alternator as it could be mounted fairly easily adjacent to the engine, problem with using ignition switch was that there is no where adjacent to mount the hourmeter and I did not fancy pulling cables to the nav table.
The hour meter is still in its box!!

It does amaze me that I would consider an hour meter as an essntial piece of kit for maintenance intervals and o/a engine life so why are they not fitted as standard to all boats ?

 

[DaveS]

I know that in the OP's case he already has his meter and just wants to fit it so this is a bit off topic, but maybe of use to others?

My boat came fitted with a Stowe Micro 200 log which I discovered could also display wind speed and engine hours if supplied with the right auxiliary connections - which neither previous owner had bothered about. I ran a wire from the log to the switched +ve on the engine control panel and thus acquired a "free" engine hourmeter. Other manufacturers also offer "extras": my Navman plotter can apparently measure fuel flow. Worth a quick glance through the manuals?

 

[rogerthebodger]

[ QUOTE ]
The thing is you know what you are doing

[/ QUOTE ]

Not according to my staff, but thats another story /forums/images/graemlins/laugh.gif /forums/images/graemlins/laugh.gif /forums/images/graemlins/laugh.gif


Don't know the 2030 I just assumed the inbuilt hour meter in the tacho would be driven from the speed pulses.

This is quite interesting and to connect an hour meter to the on power switch of the engine is the simplest but IMHO not quite correct, so trying to find a signal that was only available when the engine is running is the best solution. The W terminal will do that but as you know the signal needs converting to that required by the hour meter and the bridge rectifier is one way to get DC from the W terminal if, sa in my case the separate hour meter needs