OIL Pressure Gauge

Mac32 · Post by **Mac32** » Mon Aug 31, 2009 8:16 am

Ok I have a strange one here, but it is probably easily explainable. When the Engines are running and the gauges on the fly bridge station are disconnected the gauges on the lower helm read 30lb less. So with both sets connected the idle pressure is 70 when disconnected they are 35-40 on both port and starboard.

I will put a mechanical gauge on at some point to confirm, but I just dont understand why? Or is my boat just having fun with me.

Stripermann2 · Post by **Stripermann2** » Mon Aug 31, 2009 8:53 am

Sending units for your boat are for "dual helm" set-up. This may explain the variance in your readings. Single helm set-ups use different senders.

jav · Post by **jav** » Mon Aug 31, 2009 9:16 am

Gauges and sending units are"resistance" based devices. They operate as a matched set with sending unit on the egnine "putting out" a signal that will power 1 or 2 gauges. this is why they have single and dual station sending units.

The gauges are all the same so if you have a 2 gauge sending unit hooked up with only 1 gauge- it will not read correctly. Likewaise if you try to hook up 2 gauges to a sending unit desinged for only 1- naither gauge will read correctly.

BTW- this is also true for temperature as well as fuel level gauges as these are also "resistance" based gauges.