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Wiring Diagram-Yamaha 4.3L

Georgia Rooster

Georgia Rooster

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Anyone know where the yellow with red trace wire goes on the oil pressure switch?
20210618_114259.jpg

Georgia Rooster
 
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i would likely go to the third post on the oil pressure switch....assuming, from your picture, that the white wire feeds the fuel pump.

the oil pressure switch is a SPDT - the fuel pump wire goes to the common terminal, the starter lead (YEL/RED) goes to the NC terminal and the ignition (PUR) lead goes to the NO terminal....the starter cirsuit will turn on the fuel pump whenever the starter is engaged...once the engine builds oil pressure, the switch contacts toggle and the ignition circuit supplies current to the fuel pump. when the oil pressure subsides, the switch opens and the fuel pump stops...
 
makomark said:
i would likely go to the third post on the oil pressure switch....assuming, from your picture, that the white wire feeds the fuel pump.

the oil pressure switch is a SPDT - the fuel pump wire goes to the common terminal, the starter lead (YEL/RED) goes to the NC terminal and the ignition (PUR) lead goes to the NO terminal....the starter cirsuit will turn on the fuel pump whenever the starter is engaged...once the engine builds oil pressure, the switch contacts toggle and the ignition circuit supplies current to the fuel pump. when the oil pressure subsides, the switch opens and the fuel pump stops...
Click to expand...
This is the first bit of info I've found re: electric fuel pump, thx.
However, as a layman I need more clarification.
Could you also tell me where to find the oil pressure switch?
Thx in advance.
 
The law says the fuel pump must be turned off if the engine quits running (as a safety requirement). on a newer EFI engine, the ECU typically controls the fuel pump. On the carburetor equipped engines, the typical approach is to use a pressure switch controlled by the engine's oil pressure. the normal electrical configuration is a SPDT. IT will have three terminals, a NO (normally open), a NC (normally closed) and a C (or COM which is common). the connections are COM to the fuel pump positive feed, NO to the ignition switch, and NC to the ignition terminal on the starter's solenoid (if the solenoid has the terminal). This will allow the pump to run while cranking the engine and then once the engine starts, the switch toggles, and the pump funs until the key is turned OFF.

location - usually on the block in one of the oil galley plugs...sometimes on a TEE sharing the oil port with the gauge's sending unit.
 
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