I have an 899 at the console and an 898 at the bow. I switched transducers and using the compact on the TM. Yesterday, I noticed that the temp reading on the 899 was showing a reading from time, depth or another readout on all the screens. I checked the settings and it was set for temp. If I changed it to another reading then switch it back to temp, it would read the temp. The 899 was left on all day and throughout the day, it would repeatedly do it. Today, it no longer switches the temp to another reading but now just reads odd temps like -1 degree up to 9 degrees and it is F. The 2d just would not show arcs at all. I tried using 200/83, 200 and 83. All it will show is dots. I have sped up the speed, changed the sensitivity all the way to max and it doesn't really change much of anything but the bottom. Screen stays fairly clear of any arcs (or dots now in my case) but the DI and SI will show a good number of fish below. I even tried turning on the fish ID and it would only show a few dots still.

Does this sound like a bad transducer or the unit itself? I should have swapped out the 2 units to see what they'd do on the other transducer but didn't really think about it on the water as I wasn't too concerned with the temp. The unit is under warranty but the transducer is from the 898 and isn't. I won't be back on the water for several days and it is going to drive me crazy trying to figure out which is causing the issue. Hoping someone on here like Wayne, might have some knowledge of the issue.

Are they networked together?. Did you ever restore defaults? If you can swap heads that will isolate the problem a little more also make sure that you have the correct transducer selected in the sonar menu

No haven't networked yet.
I have restored defaults a long time ago but not for about a year.
Yes correct transducer selected.

I should have swapped heads but on the water I was just thinking that they were covered under warranty and I'd send them both in so I didn't even think about trying it. Once I got home, I realized that I had swapped the two transducers using the HD one in the rear and it wasn't under a warranty. I may just have to wait until my next days off to get it back on the water and see what happens.

I could live with the temp reading issue but the 2D really has bugged me. I use that the majority of the time.

You can't try to restore defaults, usually when something gets all quirky that will solve the issues if is settings. That is one of the first thing customer service will tell ya to do.

Finally got to take it back out but before I could switch them, the front transducer came loose and evidently the blades cut the cable so I lost my sonar there. Did switch the units and the temp was still screwed up. Reset didn't help either.

Now I need 2 transducers!