AC Oil Pressure Sensor

[Dragonten]

Has anyone replaced their oil pressure gauges on 8V71s? I have two new gauges and a dual station sending unit. I am having trouble reaching the sender and getting a wrench on it. I cannot determine the wrench size. Also the original sender has a ground and positive while the new sender only has a positive. My gauges are the original AC ones and I am replacing with Stewart Warner.

Thanks,

 

[SEVEN]

One of mine reads in correctly. I was looking for a sending unit replacement. Where did you get the set up you have? Sorry I have not looked at my sending unit to help with wrench size or hookup.

 

[Captain Ralph]

Down under the right (stb) side of the engine.
Follow the (smaller) turbo oil line down to it.

15/16" socket should fit one of them.

The two wire sender has no polarity. One lead to the gauge, the other lead to block ground.
You can ohm out the wires and figure which one goes to engine block ground.

I recall, one of the HOF members just replaced his senders, had a bug regarding the dual gauge setup and fixed it. Hopefully he can pop in and offer a better in-sight.

 

[Dragonten]

I bought the gauges and sender from Sam's Marine. Unless I am looking at the wrong thing my sender is on the left port side near the front of the engine. There is an oil line from the lower area of the block going to it.

 

[Captain Ralph]

Could be it. Same setup available on both sides.

Gauge sender on one side, alarm sender (switch) on the other side??

Your wire prints may say for sure.

 

[Dragonten]

Good point the two wires might mean it is an alarm, not the sender. I will check the wiring diagram and engine while at the boat this weekend. Thanks,

 

[Captain Ralph]

Will's Hatt is out and about so I can't just peek at his.

I recall Hobbs switches were used for low oil pressure alarms. Thought they were one wire gizmos.

 

[Captain Ralph]

I recall, one of the HOF members just replaced his senders, had a bug regarding the dual gauge setup and fixed it. Hopefully he can pop in and offer a better in-sight.

I did find this thread,, but about water temp senders.
https://www.samsmarine.com/forums/showthread.php?37613-Temperature-Gauges/page2
I thought it was just a couple of days ago. Frack time is flying by quicker.

 

[Dragonten]

So I managed to change the sender out. It had one wire on it and a neutral grounded to block, and there was an alarm sender next to it with two wires. The sender was near the front left side of engine mounted on a little rail attached to the stringer. The two gauges are now working perfectly.

 

[Captain Ralph]

So glad your working.

Another lesson to remember.

Please post the part numbers if you can.

 

[Dragonten]

Gauges are Stuart Warner up to 80 psi as is the sender. Got them from Sam's. Sorry threw the boxes away, but you can find them listed on the Stuart Warner website. Key is to have the dual station sender