First off, is there anyone in Charleston with a working 997c SI that I can come plug my unit into your boat to see if it is my installation or if it is the unit?
I have read on here, thehulltruth, and the two side imaging forums about people having the same problems as me but have seen a thread where any of it was fixed. The unit is 997c SI used in inland saltwater on an Action Craft Coastal Bay 2110TE. Here are my problems:
GPS does not hold a fix for more than 1 minute. Every day or so the unit will detect the GPS antenna (the 16 one) and find position but then loses signal almost immediately. It never says “GPS signal lost” or anything but stays stuck in the one location. Sometimes it just never sees the GPS antenna at all and the GPS screens are not available.
Depth jumps around all over the place up to over 1000 feet in shallow water. I changed the max depth to 50 feet and now it only jumps around to 50 feet. In water less than 5 feet, it will tell me 2 feet and then jump to 16 and then 10 then back 2 then 18 then 11. It is crazy all over the place. Sometimes it will hold bottom at slow speeds but other times it jumps around at anchor. It will never hold bottom going faster than about 20 mph.
I just updated to the newest software yesterday and at first it seemed to hold pretty good but after about 5 minutes started jumping around again, but no GPS signal at all yesterday. I have moved the transducer around a few times but only get the same result so I don’t believe the problem is transducer location. I first had it like in the pic below but then moved it because it was directly was seeing water coming out of the livewell overflow above the transducer and it was so close between the high-speed water pick up and the strake. I moved it over close to the trim tab on the starboard side but get the same results. I can not download screen shots because I use Mac computers and HumminbirdPC is not available for Macs. I really like the unit when it reads bottom correctly. For what I do I really need
Have you given Hummingbird customer service a call yet? It should not matter if it is under warranty or not.
Do you know that your old GPS antenna is compatible? Also, does the unit use a network whereas all components are plugged into main harness? Having a cut and taped cable makes me uneasy; especially with a networked (datalink) system. If one or more bare ends of the wire are touching eachother or the shielding, the signal can be disrupted or weakened. Given both your X-ducer and GPS signal are erratic I would guess there is a common problem.
HB recommends mounting the transducer dead center of the transom. They will tell you that SI does not work well at running speeds. The SI transducer likes clean water. Double check the frequency settings in the setup screens. May have the wrong one selected. Can’t help you with GPS problems but the cut wire doesnt sound good.
One of the Humminbird techs (Eddie) hangs out on the electronics forum at wmi.org. There are some other very helpful folks there too.
FYI … I use 2 transducers on mine. The SI for slow speeds and a standard puck style that I have glued in my bildge for traditional sonar. Switch between the 2 with a toggle. Purchased all directly from HB.
JR i have a 997 on my ranger works great i do have two transducers like pk said but i dont have to use a toggle just change the mode on the unit. the side imaging only works at speeds under 2.5 mi per hour after that you have to swap over to the secondary transducer if you want to give me a call my # is 843-305-0549 you are welcome to look at my setup or try your unit on my boat but it is going to get some warranty work next friday after thanksgiving so just let me know
I just spoke with my friend (tackle addiction enabler) in GA. He has experience with the SI and he would be very surprised if the GPS from Lowrance would work on the Hummingbird unit.
My Lowrance transducer behaved in a similar manner after I wacked it on the bottom a couple of times. Knowing you and skinny water could this be your problem with the sonar. There are probably different crystals for the side images and the bottom senders. Maybe the bottom senders are defective?