Fuel Pump Oil Pressure Switch Wiring

[Deluca92]

I'm swapping my 3.0's fuel pump from the mechanical to electrical and need a bit of guidance on the wiring. I just want to make sure i get it right before I mess something up. I'm going from the stock one plug oil pressure switch, which if I remember correctly goes to the alarm, and the larger switch is for the gauge. My question is when I install the new setup with the 3 prong switch, which of the 3 prongs do I hook the old single prong alarm wire up to? or does if have to have its own switch?

Secondly is their anywhere in the back of the boat i can safely hook up the ignition wire, or should it be run directly to the ignition?

I attached a photo of the old and new setup side by side

Thanks in advanced for any and all responses

 

[alldodge]

I'm swapping my 3.0's fuel pump from the mechanical to electrical and need a bit of guidance on the wiring. I just want to make sure i get it right before I mess something up. I'm going from the stock one plug oil pressure switch, which if I remember correctly goes to the alarm, and the larger switch is for the gauge. My question is when I install the new setup with the 3 prong switch, which of the 3 prongs do I hook the old single prong alarm wire up to? or does if have to have its own switch?

Secondly is their anywhere in the back of the boat i can safely hook up the ignition wire, or should it be run directly to the ignition?

I attached a photo of the old and new setup side by side

Here is the wiring diagram your looking for

 

[Deluca92]

The 3 prong switch I bought came with a similar diagram, however I still don't know which prong to hook the old alarm wire to on the newer switch.

 

[alldodge]

The 3 prong switch I bought came with a similar diagram, however I still don't know which prong to hook the old alarm wire to on the newer switch.

You do not use the 3 prong switch to turn the alarm on. You need to either install a 3rd port and reinstall the smaller switch sender, or rewire to use the Merc design. You have three sender/switches in your pic. The large one is for the gauge, the small one prong is for the alarm, and the three prong is to wire up the fuel pump.

Here is how the Merc wiring is done with a two prong switch (item 5).