Help needed with fp gauge install

[TREEMAN]

Bought a used Stewart Warner fp gauge & 2 sending units from another member last year & finally got around to install everything. Screwed the 2 sending units into my braided fuel line setup ,post & pre filter. They have a single threaded post sticking out of them to which I attached a wire running to the gauge. On the back of the gauge are 4 posts 3 are marked,grnd , I & S. I grounded the one & then ran the wire from the sending unit to the gauge , nothing happens ,tried it both S & I posts. Wandering if gauge needs a power source to function,if so where do I tap into one,also wandering if gauge or sending units are faulty,any way to test them?

Afraid i,m not real swift with the electical side of things so any help would be appreciated as there were no instructions .

Thanks Ian

 

[HVAC]

I have to believe the "I" terminal needs powere when the ign is on. The transducer needs power to it from which point it will modulate the voltage as it responds to pressure.

 

[TREEMAN]

Hi Nowel,thanks for fast response ,I kinda figured that might be the case,any suggestions where to splice into the igniton & any particular gauge of wire needed.

Ian

 

[HVAC]

Fuel Pressure Gauge

Treeman,



I'm not much of an electrician, but I would use a medium to light gauge wire since there is no load really. I'd use an 18 ga. wire and find a switched power source under the hood to draw from.



You might want to turn the key to the on position and then probe the wires crossing the back of the engine compartment (under the rubber flap) and find a source of power.