Marinette Boat Forum

I have lost the oil pressure reading at both upper and lower Helms. It was reading fine and suddenly both gauges do not read anything. I replaced the oil sending unit on that engine and that made no difference. I recall reading a post some time ago regarding the oil filter possibly being clogged and that you could loosen it with the engine running?? Does this sound familiar to anyone or sound like something I should try? Or, any suggestion on where to look next? Thanks

No, don't even think about messing with the oil filter with the engine running. Just change it with the engine off.(and never disconnect the battery with the engine running ) Just a few bucks, but that is not your problem. Most of the oil from the pump goes through the pressure relief valve and not the filter. The filter can only handle a small portion of the total flow. That is one reason I believe to clean the oil, dump it out and put in fresh.--- Now your problem is either gauges working and no oil pressure, or you have oil pressure and gauges and wiring have a problem. With the key on make sure you have 12 volts at the sending unit. Get a wiring diagram or draw one out, then use a VOM to find your problem.

Most likely bad ground. Oil pressure gauges seldom fail.

Simple test to start with. Disconnect the wire from the sender. Have someone watch either gauge with the ignition on for that engine. Touch the wire for the sender to the engine block. If the gauge jumps, then you know the issue is in the sender. If nothing moves, then you have an issue on the gauge side (not necessarily the gauge itself). Because you have dual stations, that means your gauges are wired in parallel. Chances are a wiring problem would be between your lower helm and the sender. For both gauges to loose a power source would be very rare, since they should share power with all your gauges for that engine.

Also, in the last year or so, I have been getting hit with faulty pressure senders. Does not seem to matter who sells them. Don't always trust new parts because they are new.

As far as the sending unit goes, did you purchase one at the local auto parts store? Sending units for boats with upper & lower helms require a special dual station sending unit (for both temp & oil). A standard automobile/single station unit won't work, as it has half (or double, not sure) the resistance value as one that is designed to operate two gauges.

You can put your mind at ease by temporarily installing a mechanical gage where the sender goes to check the oil pressure. a cheapo kit sold in auto stores will do nicely.

Jeff

I believe Hurikain has the dual station sending units.


dave

Thanks for all the advice. I do have presure indicated at my upper helm now, but still not at the lower. I did not, however, get the dual station unit.

You COULD disconnect the lower station gage and have the readings 'normal' with that sender unit. After all, what use is the lower helm readings when you're running the boat from up there?

Jeff