Can someone please let me know if my Lowrance HDS 3 could be reading outside ambient temperature rather than surface water ? My unit seems to be reading consistently higher than other fishing buds units. Mine is on 2017 Ranger. I checked unit settings and didn�t see a option for source for temp probe - thanks for any advice.

You might be pulling temp off of a hull mounted unit rather than one outboard. In addition, if your transducer is out of water on plane, it could give false readings for a while when stopped fishing.

How would I check to see which temp probe I am getting current reading ?

Put a piece of ice on the probe. Make sure you are not getting temp from the transducer in the bilge. There should be a small copper looking probe mounted somewhere near/below your jackplate.

You can change it in:

Settings..Network..Data Sources..Sonar..Temperature.

Thanks David

Thanks Squib - I will try that - should be a great indicator if it is picking up temp off probe to internal transducer

On my Onix unit I use to have, while fishing it would read one water temp but when I started the motor and idled around scanning you could watch the temp go up on the depth finder. Then when you would finish fishing it would be back down again.