Black Water sending unit

[Craig mcroberts]

I have a 52 MY and in the two years that I have owned it I have never seen the 3/4 full holding tank light in any of the three heads. Is there a way to test the system light? And if it is bad, what is the procedure and parts that I will need. Thank you in advance.

1998 52 Hatteras SD
“Echo”

[Sadey]

On our boat it’s a pressure switch that activates the light. On the top of your tank you’ll find a small black flexible line that leads to the sensor. Remove that line and while you gently blow air into it have someone watch for the light to come on. This is all after you have verified all the bulbs work. Ask me how I know how important this step is. Good luck. The sensor is available at Sam’s or other places if they are sold out and it’s a must have.

[Craig mcroberts]

Dave,

thank you very much. I will try that tomorrow.

Craig

[52CMY]

The switch is just a standard airflow pressure switch that is used in HVAC. Instead of the 1980's version original switch, you can buy a plastic body switch from Grangers or online for $14-18 that will likely last longer and be more reliable than the painted steel body original switch.