What are these senders? 12V71

[scottinsydney]

What are these two senders please? They are attached to two oblong parts on both sides of the engine. One sender has two wires and the other is a single wire. What is the oblong part?

sender1.jpg

sender2.jpg

[Glory]

Temperature sender or switch, water manifold.

[scottinsydney]

Thanks.

Is the switch 2 wires or single? Or vice versa with the sender?

What is the oblong manifold for? Is it additional cooling? They do not go the length of the engine.

[Glory]

They can both single or two wire. You can test the circuit by grounding the wire the temperature gauge is at full hot, with key on, it is a temperature sender. With engine running if the grounded wire turns on the alarm it's a switch.

That statement is if the switch / sender is working.

[scottinsydney]

Boat is 1984 61MY. The single wire was the temperature sender. When grounded the temp gauge went to maximum.I then shorted the two wire switch with the engine running, but the alarm panel did nothing. The other engine's temp switch also did not alarm when shorted. Where do I start looking please?

[oceanjake]

I’m no electrician but I believe the two wire switch is normally open and when you hit 205 degrees it closes and triggers an alarm. I believe it can be tested by connecting the two poles. That should trigger your alarm.

[scottinsydney]

On switch I bridged both poles to each other and also both poles together and individually to ground with engine running. Alarm did not work. Checked and tested system monitor and ok. Oil senders, oil switches and oil system monitor alarm working.

[MVCaprice]

On our boat that is the dual station gauge temp sender. The system monitor sender is on the back of that manifold. I would expect that unless you have extra electric gauges in the engine room it either has to be the system monitor or upstairs station gauges.

[racclarkson@gmail.com]

On switch I bridged both poles to each other and also both poles together and individually to ground with engine running. Alarm did not work. Checked and tested system monitor and ok. Oil senders, oil switches and oil system monitor alarm working.

The high heat sensors for the monitor are a NC switch. Bridging and grounding won’t do anything. Disconnect one wire or the other on any of them and the alarm will sound.