no water pressure reading

[bassgasman]

2014 F150 can not get reading on my lowrance hds 10 gen2. am i missing something almost all of the gauges show up on it but not water pressure. ia anyone else had this problem if so do you know what the cure is??

[boscoe99]

Do you have the optional pressure sensor installed?

No sensor, no water pressure.

[bassgasman]

No I do not have optional sensor installed. Where do I find out which one I need and where does it go?