FF not working ~ Help?

FF: Hummingbird 688ci

Yak: Predator 13

I installed said unit last week. I just did a temporary install for the transducer. I just duct taped it to a flat space in the bottom of the hull.

Today I took it to shadow cliffs for the first time. It gave me a temperature reading, probably not true water temp. Also got Long and lat. Also got speed.

What I didn't get were fish or structures. That part of the screen is just blank.

I'm sure it's my fault. I just don't know what it is?

Any suggestions please?

Taped the transducer inside or outside the hull?

could be that there is air between the hull & transducer.
1st things to check would be the connections, and then the way the transducer is fixed to the inside of the hull.
My transducer is stuck in a wad of "ductSeal" putty (was a temp install, but just became permanent in that it has held up well).
twice now, cargo in the hull has dislodged the transducer and the screen was just blank like I had no power to the unit. the great thing about the ductseal is that i just pushed the transducer back into place with a fresh wad of putty and that solved it.

could be that there is air between the hull & transducer.
1st things to check would be the connections, and then the way the transducer is fixed to the inside of the hull.
My transducer is stuck in a wad of "ductSeal" putty (was a temp install, but just became permanent in that it has held up well).
twice now, cargo in the hull has dislodged the transducer and the screen was just blank like I had no power to the unit. the great thing about the ductseal is that i just pushed the transducer back into place with a fresh wad of putty and that solved it.

You beat me to the "long version" 

Yeah, transducers don't sound thru air.  IF it is inside the hull, it needs to be in a 'water bath' (ie. no air between the transducer face & the hull).  IF it is outside the hull ... you have other problems.

Plenty of FF install threads in archives in addition to the sound advice you just got

Yeah, transducers don't sound thru air.  IF it is inside the hull, it needs to be in a 'water bath' (ie. no air between the transducer face & the hull).  IF it is outside the hull ... you have other problems.

+ 1

Been there! Info here and advice from NCKA brothers while on the water solved it.

Thank you.

I just put duct tape over it.So I'm sure there's air under there. I'll check it out tomorrow.

What would be a good way to put there temporarily in case I have to move it?

Put it in a plastic bag full of water then tape it down

Thank you, zip locks I have. 

Put it in a plastic bag full of water then tape it down

+1  Makes a good way for temp. install or test out locations before perm. install

Why not mount the transducer in your Predator 13's dedicated transducer scupper?

Why not mount the transducer in your Predator 13's dedicated transducer scupper?

Because the Transducer that is compatible with the scupper hole does not work with down imaging or my FF. Someone on here did post a way around that with the transducer that I have but it looks like the transducer could get damaged if I'm not real careful. I'd rather just put it inside where I know it'll be safe.

Why not mount the transducer in your Predator 13's dedicated transducer scupper?

Because the Transducer that is compatible with the scupper hole does not work with down imaging or my FF. Someone on here did post a way around that with the transducer that I have but it looks like the transducer could get damaged if I'm not real careful. I'd rather just put it inside where I know it'll be safe.

Yes, I posted the links to instructions for mounting your down imaging transducer in a Predator 13. From the pictures in the links, it looks like the transducer is mounted in the recessed transducer cavity, so it should not get damaged. The transducer is built to handle abuse, with all the electronics potted in epoxy and surrounded by a tough plastic shell.

And as you have already realized, you will lose accurate water temperature readings by mounting it inside your kayak.