Topic: Temperature UNCONNECTED on new 788ci HD

[Robert Brown]

Just had a new out of the box 788ci HD installed this week on my console at my local boat dealership, with temp probe running out the back of the transom.  First time on the water this morning, everything, including temp, doing fine.  (Water temp was 80.2F displayed on the unit, which matched with a Lowrance unit I also have on the boat).  After a few hours it started reading between 110-120 degrees F.  Then eventually the temp display disappeared from the temp windows.  From the System Status Accessory Test page it now shows "Temperature UNCONNECTED".  I've confirmed no pins are bent on the head unit, I uploaded latest software (6.640), and confirmed that the temp sensor is still there.  I think what I might have witnessed is a melt-down of the temp sensor and I will have to get it replaced.  This is unfortunate as it is a brand new unit and such an effort to get the boat in to the dealer.  I searched through this forum and was hoping to find the magic answer that would fix me up.  I have initiated an inquiry in through Humminbird service website.  Any thoughts?  Thanks in advance.

[Humminbird_Greg]

Welcome to the Side Imaging Forums Robert.

Sorry to say but I think that your only option is to replace the temperature sensor here.  Is this a separate accessory or is this the one from the transducer (XP-9-20-T)?

[snowman48047]

I have been experiencing thie EXACT same problem with my 787c2i.  I was under the impression that the temp sensor was part of the speed sensor.  Are they different?  Is there a seperate temp sensor?  My speed reads ok comparing to handheld and speedo on dash, but my temp will read 118 degrees.  I can turn unit off then on and it will reset the temp but it doesn't read correctly for long.  I've had the temp sensor for 8 years...

[Humminbird_Greg]

On most of the standard transducers Humminbird has the temperature sensor is built into the transducer.  There is a separate temp sensor available (TG-W) and a Temp/Speed sensor (TS-W).  You will have to check your boat to see which you have installed.

[Naveed123]

This is very very nice and wonderful post..............................

[snowman48047]

Robert, have you fixed this yet?  I have noticed on mine that if the temp reads 100+ degrees, the temp display will start to flash after  awhile.  I can then turn the unit off and then back on and it will work all day.  Mine is the TS-W, temp /speed sensor.