temp sender?

i will try to make this short. temp sender for gauge. i see the replacement one ask one station or two? ihave a 1976 silverton two station. if only one station is being used other station ing is off why do you need atwo station sender or dont you . my crusaders where replaced with new chev 350s. carbs alt sea pumps are no longer crusader stuff.but the wireing i believe is still the same. i have one wire going to each temp sender. gauges on both stations work fine when useing one station at a time. iwas told when i bought the boat if you are in upper station doen stairs station should be off and vise versa. i guess what im asking is how would i know what sender i have?

If you only have one station (set of gauges) powered on at a time, use the single station sender. If the upper and lower stations' gauges are powered on, you will need the dual station sender.

For the gauges to register with some level of accuracy, the sender needs to provide a given level of resistance so an expected amount of current flows thru the sender. Two gauges driven by the same sensor requires twice as much current flow which means the sender needs to provide 1/2 as much resistance (as a single station sender).

The 1976 silverton two station boat is very likely wired with the two helms in parallel, meaning that when the lower helm is powered up, so are the upper helm instruments, and visa-versa.
The paralleling occurs within the main hull harness.
Being in parallel is why the senders are specific to the number of instruments.
The two are not the same, so if/when replacing, you must stay with the same resistance sender... I.E., dual instrument sender.
Same for oil pressure as it is for temp.

BTW, if yours is set up similar to mine, each station key switch can be ON simultaneously, however, if at the upper helm and you needed to kill an egine, you'll not be able to if the lower helm key is also ON.

I'll sometimes fire up both engines from my lower helm. When I go to the upper helm, I must remember to turn the lower helm key switches OFF, and/or visa-versa.
Same with blower motors, nav lights, anchor light, and I could include the momentary switches for horn and tilt.

Bottom line, I'm fairly sure that you'll want the dual station senders.

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