I am hoping that you guys may be able to help me out with my fish finder issues (Humminbird 998c)... I bought a BassCat Pantera Classic a couple of months ago. Going into the deal I knew that the depth finder was not functioning correctly. The depth constantly shows 1.6 ft. no matter where I am on the water. Every now and then it will start working for no apparent reason. The only thing I can think is that it gets into a certain position that allows it to work, it will work for a minute or two and then go back to good ol' 1.6 ft deep. The strange thing is that the side imaging works along with the GPS/speed/etc all the time.

The boat came with a new transducer (the old unit was stolen and the owner bought the exact same Humminbird unit, but didn't bother replacing the transducer since it worked at the time). I am hoping that putting the new transducer on will fix my issues.

Have any of you experienced this before with your fish finder? If so, what was your solution?

I have installed a transducer on my old jon boat... but fiberglass is a different animal. Below I have some pictures of where the current one is on the boat. Is this a good location for it or should I position it somewhere else on the transom?

I appreciate your help!

You will never get readings much above idol speed with that location. You either need to drop it down or the most common route is to run 2 transducers. One shoot thru and leave the hdsi transducer where it is. The current location is out of the water when moving at faster speeds

Worst location I've ever seen for a transducer location. At least your problem is easily solved.

Move it to the strake to the left of the one that your trailer bunk is on. Screw it into the red part of your hull so the transducer is flush with the bottom line of the hull. It needs clean water to work correctly and it doesn't have a chance where it's at.

I tried to find you a photo but can't post it directly. Scroll down this thread and see the photo showing where I'd mount it..

http://basscatowners.yuku.com/topic/26563/Transducer-Transom-vs-Through-Hull#.V4Ww_JA8KrU

I have had the same thing happen. The 2 D sonar reads at high speed.Go to reset factory defaults and start there. Then if that does not work try to unplug the y cable to the sonar thru hull and see if it does it. It is most likely the Y cable IMO.

As far as location of that SI/DI transducer mine is about the same area and I can just about see a fishes eye ball. I get great pictures/performance from that location. Just watch going over stumps dead center it could jerk it off.

Need to pull that loose cable up through the jack plate IMO.

Thank you for the advice. I need to check and see if there is a through hull transducer being run to the unit as well. I assumed that the DI/SI transducer could also do the regular 2D sonar.

I have mine mounted in the same spot. I had it lower and ripped it off, so I raised it. I lose SI at about 6 to 7 mph, but I deal with that instead of 250 more dollars to replace. That is your Side Image and Down Image transducer. I am guessing there is another sonar trans. in the hull. Also guessing that is the problem or even the Y cable. I would unplug the one coming from the sonar trans. and see if that clears up your depth reading. If so you know it is in the cable or the mounting of the shoot ,thru transducer. If it doesn't fix it, then I would guess what Marc said above. Unplug the si cable and plug directly into the back of unit.

Since you have the other "NEW" transducer, mount it to a board and go to the lake, hook up the "NEW" transducer, place the new transducer down into the water and try to get level with the bottom and see if it gives you a good reading or not. Does not really cost you anything to try this.
Then if that works, you have to move from where you have it mounted to a new spot on the drivers side just below the lowest part of the bottom of the boat(FLAT PART). Look at the new transducer and there will be a mold line where the plastic part is. About 1/4 inch up from the bottom of the transducer. That has to ride below the very flat bottom part of the boat. I would suggest you get the plastic transom saver part at bass pro so you don't have to drill a bunch of holes in your transom for any other transducers in the future. Hope this helps

You are forgetting something with the testing advice. When the Y cable is used, the 83/200 kHz crystal in the SI transducer is disconnected, there is no electrical connection for it.

Just unplugging the shoot-thru from the Y cable and testing for depth/2D sonar won't work since there is no circuit for 2D sonar on the SI side of the Y cable. To test a shoot-thru with the correct installation, the shoot-thru has to be connected directly to the display--NO Y cable.

To test the display for proper 2D function, connect the SI transducer directly to the display-NO Y cable.

The PROPER SI installation for that hull is as shown along with using a shoot-thru XP 9 20 transducer in the bilge using the AS SIDB Y cable to connect the two transducers to the display.

I would drill a hole at the bottom rightside of the jackplate.. Get it up and some what protected, ck out how most ducers (SI) on skeeters are mounted..

If you don't have a thru hull Xducer, you might do like I did and mount a cheapo fish finder and use that one to read your depth on plane. It was cheaper to buy another unit than it was to buy the thru hull.

Thanks guys. I'm going to try a few of these things tomorrow and let you know what works fixes the issue.

If you end up re-mounting it, i'd get myself one of these.

http://www.sternsaver.com/

Update:
I got try a few of the suggestions you guys gave me today on the water... First, I tried adding several cups of water to the bilge to get the thru-hull transducer to work, but no luck with that.

Then I tried hooking up the NEW SI/DI transducer (which has the capability of regular 2D sonar) directly and it worked great just holding it off the side of the boat... BUT I wanted to figure out where the problem was, so I hooked the old SI/DI transducer that is still on the transom up directly to the back of my Humminbird, and all of the features worked, they were just a lot more blurry than the new transducer (at least I know replacing that will help).

After that, I tried hooking the 2D transducer (thru-hull) up directly and still nothing, just 1.6 ft deep the whole time ( transducer was still submerged under water in the bilge at this point).

I settled with wiring the SI/DI transducer directly for now so I have depth readings at least... but i lose depth at 8mph with the location of the transducer on the transom.

Now the question is do I buy another thru-hull transducer and replace the old one or just move the SI/DI transducer to where I can get better readings and be done with it? How much do the 2D thru-hull transducers run?

Any advice y'all can offer after the update would be great. I have already learned so much over the last couple of days from you on fish finder wiring. Thanks!

Madison Hitt

If you want 2 D then replace the transducer in the hull. It is the only one that works at high speed.Which will keep you from running up on ground. I use mine so I would just replace it and have everything working. IMO