Engine Hour Meter Fuel Pressure Switch

[rustybucket]

Ok, since I've had our 52c the engine hour meters are non-functional. I've been keeping up with engine hours manually, which is not a huge deal but I'm ready to tackle the issue.

I thought for certain it was just my hour meters that had gone bad. So I purchased new meters and sure enough they do not work either.

So I pulled out my hatt wiring diagrams (should have done this first) and find that a fuel pressure switch is what relays power to the hour meters.

Does anyone have any guidance as to where this fuel pressure switch is located on an 8v92TA on a 1986 52c? I've searched the internet and manuals and come up empty. Any guidance would be greatly appreciated.

 

[finatic]

I'm interested in this one! Several years ago my port engine was replaced and the meter hasn't stopped since!

 

[steve c]

I could use the same information for 671tib Covingtons !

 

[racclarkson@gmail.com]

Ok, since I've had our 52c the engine hour meters are non-functional. I've been keeping up with engine hours manually, which is not a huge deal but I'm ready to tackle the issue.

I thought for certain it was just my hour meters that had gone bad. So I purchased new meters and sure enough they do not work either.

So I pulled out my hatt wiring diagrams (should have done this first) and find that a fuel pressure switch is what relays power to the hour meters.

Does anyone have any guidance as to where this fuel pressure switch is located on an 8v92TA on a 1986 52c? I've searched the internet and manuals and come up empty. Any guidance would be greatly appreciated.

On your secondary fuel filter. Hobbs switch.

 

[Scarlett]

What Robert said, round fitting on secondary fuel filter housing, Sams has them. Have you noticed that your alternators are not working because in most setups this switch also supplies excite voltage to the alternators. There is also the option to feed the hour meters directly from the key switch.

 

[rustybucket]

On your secondary fuel filter. Hobbs switch.

View attachment 33208

Ok, well that explains it... I do not have that switch. Pretty sure during the rebuild my cannister filters were switched to spin on, guessing the switches left with the cannister filters.

I need to check to see if the wiring is in place and add them back.

 

[jim rosenthal]

Would it be simpler, if they don't work, to wire them from the key switch directly and skip the fuel pressure sender altogether, if he doesn't have them?

 

[R D Young]

If you do use the fuel pressure switch, make sure that the hour meter and the alternator exciter are on the same side of the switch - doesn't matter which one as long as it is the same side. Otherwise you will have 24-7 hours going and also a hot alternator. The source wire should be all red (from x03 on panel) and the return line is red with a white or black stripe (to x04 on panel). As I remember, the alt wire goes directly to the alternator.
If you want to go through the ignition, you can jump it through wires x16 - not worth the effort.

 

[dsharp]

Would it be simpler, if they don't work, to wire them from the key switch directly and skip the fuel pressure sender altogether, if he doesn't have them?

The problem with doing it this way if you leave the key on it’s racking up hours without the engine running. Not really that big of a deal. That’s why they use fuel or oil pressure switch to complete the circuit

 

[rustybucket]

The problem with doing it this way if you leave the key on it’s racking up hours without the engine running. Not really that big of a deal. That’s why they use fuel or oil pressure switch to complete the circuit

I've had several of my guys leave the keys on during trips, we often dead boat drift or go to one engine during a trip. Never fails, nobody turns the key off.