Wiring up an engine hours meter

[Swanrad2]

Evening,

Having (nearly) fixed the engine I decided the addition of an hours meter would be a good idea - hours since refit, filters etc. I bought one. It arrived. No wiring instructions. Anyone know how to wire the thing to a Diesel engine so it only runs when the engine does (obviously) ? Personally I would take the +ve from the alternator, about right?

Cheers.

 

[West Coast]

Doing the same for my VP 2003. There will be a positive switched supply on your engine panel, which becomes live when you switch on the panel, before starting the engine. Do you have an engine wiring diagram?

 

[MoodySabre]

I second that - just wire it into the ignition switch. It only runs when the switch is on and its only on when the engine is running.

 

[William_H]

The above solutions will not give accurate engine hours if the power to the engine ("ignition" when it is not really ignition) is turned on before engine start or left on eafter engine stop. Probably OK for your purposes but will keep counting if engine is stopped and power not switched off.
In a standard set up for alternator charging the output line is connected directly to the batteries at all times. This means clock will tick over at all times batteries are turned on.
A vsr could be used to sense when the alternator is charging. ie engine is running.
A relay could be connected to detect when oil pressure switch has operated so turning light off. The relay is wired to operate when oil light is on. The power for the clock comes from the engine panel power on via normally made contacts on the relay so contacts open if no oil pressure. (the relay converts a logic 0 to a logic 1.)
Another option is to switch a relay with the ouput from the W or Aux sense terrminal on the alternaor which has a kind of pulsed Dc (or is it AC) when alternator is charging. This is about 6v average so may need a sensitive relay. The relay switches the clock on.
There are few options good luck olewill

 

[VicS]

What William says may well be right but the common practice is to wire as suggested to an "ignition switch" controlled circuit. In later VP panels ITYWF thatthe hour counter was simply part of the tachometer and ran while power was applied to the tacho and other instruments.

Your engine control panel has a tacho I assume. Connecting, via a fuse, to the power supply to that may be the easiest thing to do

 

[rogerthebodger]

I wired my engine hour meter with the positive to the ignition switch and the negative to the oil pressure switch which closes when oil pressure is above 10psi so it only runs when the engine is running with oil pressure.

If the oil pressure switch is closed with no pressure a relay of transistor con be used to reverse action.

If you have a water flow switch like the RS one that could also be used in a simular way.

 

[Sandy]

I note the engine hours in the log. Simple and works every time.

 

[Plevier]

When the original counter on my VP 2020 failed (as normal!) I wired an electromechanical rather than LCD counter to D+/61 on the alternator. With "ignition" on and engine stopped that only shows about 5V, not enough to start the counter running so it only records genuine engine running hours. Also you can read it power off, and it's fitted in the engine bay rather than chopping an extra hole outside near the control panel..

 

[Swanrad2]

What William says may well be right but the common practice is to wire as suggested to an "ignition switch" controlled circuit. In later VP panels ITYWF thatthe hour counter was simply part of the tachometer and ran while power was applied to the tacho and other instruments.

Your engine control panel has a tacho I assume. Connecting, via a fuse, to the power supply to that may be the easiest thing to do

That'll do for me- the is a tacho so I will piggy back off that.

Thanks

 

[Swanrad2]

When the original counter on my VP 2020 failed (as normal!) I wired an electromechanical rather than LCD counter to D+/61 on the alternator. With "ignition" on and engine stopped that only shows about 5V, not enough to start the counter running so it only records genuine engine running hours. Also you can read it power off, and it's fitted in the engine bay rather than chopping an extra hole outside near the control panel..

Same type - but as I never leave the engine ignition on when its not running and the switch is easily accessible from the engine bay I think I will go with the ignition switch. I am also making another smaller 'instrument panel' for a fuel gauge, the hours meter and a battery condition monitor, none of which exist a the moment.

 

[Rock Dodger]

Wired my hours run meter to the engine key switch. When it is turned on the buzzer makes a racket until engine starts and when switched off buzzer sounds again until key is switched off. That small amount of time isn't relevant to the time between oil changes etc. I put mine in a panel I made up. see pic.

 

[nigelmercier]

The above solutions will not give accurate engine hours if the power to the engine ("ignition" when it is not really ignition) is turned on before engine start or left on eafter engine stop. Probably OK for your purposes but will keep counting if engine is stopped and power not switched off...

I get an alarm if I leave my ignition on for more than 30 seconds, so I've always considered this to be a perfectly acceptable solution.

I was surprised to discover that the VP tachometer counters do actually require a tach signal to count, which in my case is a PITA because I want to set my new one to the correct reading. A little messing around with a signal generator sorted it out.

 

[Swanrad2]

Wired my hours run meter to the engine key switch. When it is turned on the buzzer makes a racket until engine starts and when switched off buzzer sounds again until key is switched off. That small amount of time isn't relevant to the time between oil changes etc. I put mine in a panel I made up. see pic.

View attachment 40390

Thanks - what is the material the instruments are mounted on?

 

[Rock Dodger]

It was made from material that, I , Er...acquired. The aluminium is good quality and I am told it is corrosion resistant. See pics...

 

[VicS]

It was made from material that, I , Er...acquired. The aluminium is good quality and I am told it is corrosion resistant.

So you are the one who nicks the diversion signs leading to us all rushing round like chickens with no heads trying to find which way we should go!

 

[Rock Dodger]

No VicS, I did acquire the sign legally, honest. After carrying out roadworks, a contractor left a lot of stuff dumped on land I administer and after several requests to remove it I got fed up and sorted it myself. Anyone want some solidified tarmac?

 

[nigelmercier]

It was made from material that, I , Er...acquired...

ROFL!

As an aside, if one wanted to go the plastic route, what would be best?

 

[Swanrad2]

It was made from material that, I , Er...acquired. The aluminium is good quality and I am told it is corrosion resistant. See pics...

View attachment 40422View attachment 40423View attachment 40424

Oh, brilliant!
Balaclava - check.
Gaffer tape on reg page - check.
Road works - check
Go, go, go.

 

[Rock Dodger]

ROFL!

As an aside, if one wanted to go the plastic route, what would be best?

See if you can obtain a material called "Traffolyte". I think that is a generic name, there are other similar materials for labels available. This is a rigid plastic material which can be bought as a laminate made of different coloured layers to enable it to be engraved. This will give, for example, white lettering on a black background. It is also non-conducting. If thick enough it can be drilled and filed to use as a panel on the front of a switch box. I have found it to be a bit brittle so get it thick enough to take the stresses.

 

[Swanrad2]

See if you can obtain a material called "Traffolyte". I think that is a generic name, there are other similar materials for labels available. This is a rigid plastic material which can be bought as a laminate made of different coloured layers to enable it to be engraved. This will give, for example, white lettering on a black background. It is also non-conducting. If thick enough it can be drilled and filed to use as a panel on the front of a switch box. I have found it to be a bit brittle so get it thick enough to take the stresses.

I have a fairly big, thick length of what I will call 'sign makers plastic' - I would have once called it Perspex, but not so sure anymore. Though about using that as it would look quite nice. Any good?

Also got a blue bit that is the same colour as the spray hood - thinking of making a set of semi-opaque wash boards out of that. Love recycling.