Hour Meter Wiring

[Sweet Pea]

Is there a way to wire the hour meter so that it only runs when the engine is actually running? My meter starts counting as soon as I turn on the ignition. I often leave the key on so I can start the engine without having to go below and turn the key on.

[Dolce_Vita]

Is there a way to wire the hour meter so that it only runs when the engine is actually running? My meter starts counting as soon as I turn on the ignition. I often leave the key on so I can start the engine without having to go below and turn the key on.

If you have an Atomic 4 with an electric fuel pump, it will be equiped with an Oil Pressure Safety Switch (OPSS) that cuts off power to the pump when the pressure is below 5 psi.  You can wire the hour meter in parallel with the fuel pump, and it will count hours that you have oil pressure.  Close enough.

If you have a diesel, you can still put an OPSS on the oil system somewhere (not sure exactly where, being an A4 man myself) and power the hour meeter thru it for the same effect.

One final note of warning:  On A4 systems, it is not good to leave the ignition on without starting for long periods of time.  It can result in overheating of the coil and it's ultimate failure.  The symptoms of the failure are very similar to a fuel problem, making it hard to diagnose.

[Sweet Pea]

Thanks for the reply. I should have stated that I do have the Volvo diesel. There is a low oil pressure alarm wired to the oil pressure switch but i'm not sure if I can hook into that. I didn't know about the coil problem with leaving the key on with A4s. Do you think that applies to the diesel engine as well?

[Dolce_Vita]

Thanks for the reply. I should have stated that I do have the Volvo diesel. There is a low oil pressure alarm wired to the oil pressure switch but i'm not sure if I can hook into that....

No, you can't.  The low-pressure switch closes when the pressure goes below its setpoint.  You want something that opens below its setpoint.  That's what an OPSS does.  You can add one to your Volvo by either finding an unused oil port and installing the OPSS in place of the plug, or by removing your low-pressure sensor and replacing it with a tee so both sensors can be attached.  An OPSS can be purchased here: http://www.moyermarine.com/ , part no FPMP_04_46.  Or search for "safety switch".

Another possibility is a switch that has both normally-open AND normally closed contacts.  One such switch id the A68301 manufactured by Carter.  Summit Racing has it:
http://www.summitracing.com/parts/crt-a68301
It can be installed in place of your existing low-pressure warning switch, and do both functions.

 

...I didn't know about the coil problem with leaving the key on with A4s. Do you think that applies to the diesel engine as well?

No, it doesn't.  A diesel engine does not have a coil.

[Sweet Pea]

Thank you for the great info and links!

[popeye323]

To solve the problem of the hour meter not running and having to go below to turn the key on  my 323 with a diesel, I wired in a second key switch in the aft portion of starboard coaming box. It was a fairly simple process of splicing into the hot side of the ignition wire and mounting a key in the coaming box.. When I want to get underway I turn on the original ignition key located down below and then I turn on the second key located in the starboard coaming box and hit the start button as normal. When I'm done motoring I just reach in the coaming box and turn off the second key. This system requires a second ignition switch and it helps if both switches and keys are keyed alike to keep it simple. It also acts as a thief deterrent because both keys are required to be on. The second key is at the aft end of the coaming box out of site.  It works for me.