Depth/Sonar Transducer C28

[Jeff58]

Hopefully this might help others.
Launched our 2014 C28 last week and the depth gauge and sonar did not function on the Garmin 7212 Chart Plotter. Garmin product support was great and went thru diagnostics starting with software, locating the GSD and checking the LED status light, before jumping to the transducer. The transducer located next to the shower sump was bonded to the floor and under examination popped off the bonding sealent. Dried out and brittle. The mystery was no one could identify the Airmar model. Everyone thought it was a P79, however it had no bottom mounting flange and would not open (read all the posts about glycol fill). Sent pictures to Airmar and they said, "thought they had seen everything". The unit was bonded to the hull without the base which holds the glycol! It was in fact a P79-6G (less the base). They were surprised it ever functioned. New one ordered...not looking forward to trying to route the cable...old one is apparently zip stripped a couple places so I can't use it to pull. Will try and post a couple pictures of the old one and the mount.
gallery2.php?g2_itemId=68389

 

[Cutwater28GG]

Yep Ranger had a habit of bonding the unit straight the hull and not using the glycol cup.
mine experienced the same issue as yours. it appeared glued on but in fact the bonding had failed with a hairline crack which reduced the audio transmission resulting in no sonar.

I reinstalled with the glycol cup.

I was able to peel the glue off the bottom of the transducer (as it was very brittle) and reuse. This removed the need to rerun the cable which is not an easy task. you may have to move the fresh water tank to get to the shower sump.

my thread on tugnuts http://www.tugnuts.com/viewtopic.php?f=5&t=11272&hilit=+sonar

 

[Jeff58]

Ground the hull with a Dremel tool, cleaning up the residual dried bonding putty, installed the new cup and was able to clean the old transducer. System worked. I was not looking forward to trying to route the new cable!