Battery/Engine Off - Get Low Oil Press and Ticking

[jviss]

Almost ALL production boats used them. Not only Catalinas. They still are doing it, all of them.

Stu, I was going to say "bullsh*t," but on second thought, I don't think that's strong enough. "They are still doing it, all of them." Really? Maybe we don't agree on the definition of 'production boat.' More than five of a design? Or, 25? 100? Would Hinkley, Tartan, Sabre, Alerion, and so on? I know, there aren't many still around, or even building sailboats in the 30 to 40' range, but still!

Is Catalina still using trailer connectors? Hunter? Benetau?

Ha ha! All in good fun, but curious.

 

[jviss]

Sounds like you have two issues 1) your lift pump is getting weak and should be replaced. 2) you need to investigate the wiring. With the switch off the only thing powered should be bilge pumps, battery monitors and radio preset power. Trace all your wiring and see where you are bypassing the switch

Les, I have no idea where you came up with this. Why is the lift pump weak? More importantly, what switch are you talking about when you say "With the switch off the only thing powered should be bilge pumps, battery monitors and radio preset power." I think the O.P is referring to the engine keyswitch, not the house power switch.

 

[LeslieTroyer]

You said the lift pump would stop ticking if you hit it. The only thing that should stop the pump is reaching pressure. The way these pumps work is by pushing a piston When it makes it to the other side the selonoid is deenergised and a spring pushes it back. Unless you have a bleed screw open your pump should stop and keep up the pressure. If the pump has leaky one way valves it loss of pressure will cause the piston to complete it travel and go thru it's cycle again. I've had this style apart many times on my Alfa Romero and can tell you for sure they should stop pumping when correct pressure is reached.

The switch I was referring to was the only one mentioned in your post. The off/A/B/Both switch. With it in the offposition your engine and lift pump should have no power. Typically the only items not turned off are the items I mentioned. Some will argue the VHF should be on the list, but no one would put a liftpump on the always on list

Les

 

[jviss]

Les, I'm not the original poster. That said, the only way the fuel pump can run, and the low oil pressure light illuminate, is if they are powered. If the keyswitch is in the "OFF" position and the pump is running and the light is lit, it must be a faulty switch.

I find it humorous, the many theories expressed here that ignore this simple fact.

 

[marchem]

Les, I'm not the original poster. That said, the only way the fuel pump can run, and the low oil pressure light illuminate, is if they are powered. If the keyswitch is in the "OFF" position and the pump is running and the light is lit, it must be a faulty switch.

I find it humorous, the many theories expressed here that ignore this simple fact.

I thought the PO said he replaced the switch, with no change. It is puzzling, but I still think careful testing with a volt meter should expose the cause. It's not rocket science...

 

[jviss]

If the pump is running, and the oil light is on, then they are energized. No other explanation. Maybe not the keyswitch, could be a short in the harness, but no doubt, those circuits remain energized after the switch is shut off.

 

[marchem]

If the pump is running, and the oil light is on, then they are energized. No other explanation. Maybe not the keyswitch, could be a short in the harness, but no doubt, those circuits remain energized after the switch is shut off.

I agree.

 

[LeslieTroyer]

. If the keyswitch is in the "OFF" position and the pump is running and the light is lit, it must be a faulty switch.

I find it humorous, the many theories expressed here that ignore this simple fact.

I gues I'm in the camp that is Dodgy wiring rather than a bad switch. But it could be the switch

 

[Bluetrees]

If the pump is running, and the oil light is on, then they are energized. No other explanation. Maybe not the keyswitch, could be a short in the harness, but no doubt, those circuits remain energized after the switch is shut off.

I would also agree but think about this, if there is a short somewhere that energizes the low oil pressure circuit and powers the lift pump (symptoms) how is it that tapping the lift pump apparently removes the power from both? both symptoms are gone with just a slight tap to the lift pump.
And yes, the key switch was replaced.
I say this not to dispute your inputs but to add to your thought processes.

 

[jviss]

That is indeed a mystery. Perhaps the vibration from tapping the pump opens the short. Where is the pump located?

By the way, now would be an excellent time to examine your connector, from panel to engine. You could have a fire waiting to happen.

 

[marchem]

That is indeed a mystery. Perhaps the vibration from tapping the pump opens the short. Where is the pump located?

By the way, now would be an excellent time to examine your connector, from panel to engine. You could have a fire waiting to happen.

I agree, the tapping must be affecting the short. Looking at the schematic more closely it looks like a problem (short) with the preheat solenoid could cause the lift pump to energize and the oil pressure alarm to sound.

The C310 does not have a gummy bear connector. There is a terminal strip in the panel, but the wiring runs direct from there to the various connections on the engine.