Volvo Penta 2003T

[Tcubed66]

I have a Volvo Penta 2003T with deluxe (alternative B) wiring panel. I’m kinda confused on the wiring for the oil and coolant. My engine coolant has a two prong sender and oil a single wire but the schematic shows 4 sending units. Is this just a depiction or actual individual senders?

[tkeithlu]

It's entirely possible if the panel has both gauges and idiot lights for oil pressure and water temperature. Senders for gauges "send" a variable resistance; the gauge is just a voltmeter or potentiometer. Senders for idiot lights are switches that close when oil pressure is low or temperature is high.

[jamhass]

The oil sender should have 2 prongs, one for gauge, one for the idiot light and buzzer. If you really only have 1 prong, either one broke off (not uncommon) or someone replaced the sender with the wrong unit.