Data Marine Speed Log question

[John]

When I bought my used Catalina 27 several months ago, it came with a Data Marine Speed Log. The thru hull transducer/wheel was in very bad shape so I took it out and replaced it with the proper Data Marine replacement. When I plugged it into the exisiting cable from the unit all Zero's came onto the units display screen. However, that is all that is happened. It doesn't come off the zero's in either the speed or the distance. I hit the reset switch and still nothing. Can anyone help me with this? Thank you.

 

[John Squire]

Could be several things

Double check electrical connects - an ohmmeter is the most reliable way.Based on the language in your post, it sounds like the old transducer wasn't the same as the new one - I don't know your unit, but I'll guess the calibration should be checked.Pull the transducer and make sure it isn't fouled with barnacles, etc. You should have an appropriate plug on hand, of course. While it's out, test it by spinning by hand or with running water. If you don't get anything on the instrument, check the connect end of the cable with a multimeter (set for a very small unit of VDC) when the wheel spins.Check the alignment axis when you reinstall to ensure the paddlewheel axel is abeam.A tight coil of extra wire/cable can cause induction problems - a loose figure 8 is the best way to stow leftover length.