fuel mngt system not working

[sergio389]

My Yamaha Fuel management system stopped working a while back.It just shows a "0" display. I made nothing of it for a while, BUT, now I decided to fix it. Took both sensors (twin 200HPDI's) out, cleaned well (not really dirty at all), replaced BOTH harnesses, AND still not working! Gauge shows a display reading of "0". WHAT NOW? HELP!
SERGIO389

[boats.net]

You can remove flow sensors and connect harness back to it and blow compressed air through sensor to see it getting a reading, can connect to ohm meter to see if get reading.

[islandyam]

You can remove flow sensors and connect harness back to it and blow compressed air through sensor to see it getting a reading, can connect to ohm meter to see if get reading.

how do you do the ohm test?
I don't have a compressor.

[rodbolt17]

your going to need an air compressor,regulate it down to about 25 PSI.
dont wanna kill it.

its a 5v hall effect device.
as the paddle wheel passes the magnet coil it feeds back a digital type square wave,well not quite sqaure but close.
so between the orange and black you should see 5 v.
when the paddle spins you should see a pick off between the pink and the orange.
remember we have to have three correct paths.
5v to the sender,ground from the sender and the pick off. lose any one and it reads 0.