Macerator Relay Failure and replacement

[Gary.Jones]

With more than a little down time available right now, I thought I would start a thread that deals with a problem that occurred during our recent 3 month trip on the road in the SouthWest early this year. At some point, I wanted to dump black and gray holding tanks, and when all set for the process, turned on the black tank first, and switched on the macerator and…… NOTHING! No macerator motor running, no nothing. So began the process of trying to figure it out. As it turns out, it was not a big problem, thankfully!

First issue was whether the motor was jammed or bad and if the switch was working. Decided to tackle the switch issue first. A call to Entegra Customer Service told me that I could test the switch fairly easily first by removing the metal panel in the wet bay that hides the dump valves and mechanism. My CS fellow asked me to see if there was a clicking sound when I moved the on-off switch from off to on. I could hear no clicking until I removed the metal panel exposing the valves and inner workings of the holding tanks. And then it was clear that there was no clicking sound. The clicking sound would come from the relay that is activated by the switch and happens to dangle down from the ceiling of the wet bay section on a short section of cable of about four wires. I could also then activate the on/off switch while holding the relay in my hand and quickly tell that the relay was not working, indicating either that the relay had failed or the switch had failed. The first picture shows how the relay hangs down from the ceiling area in the wet bay. The second picture shows the relay socket with the relay removed.

As it turns out, the relay simply plugs into a matching female connector and can be removed simply by pulling the relay away from the connector. I carry a Fluke Digital Volt Meter (multi-meter) with me which lets me test for continuity and with the relay removed and the female contact connectors open, I could easily figure out the wires which activated the relay. The switch was good. It was the relay that was bad. The third picture shows a schematic diagram of the relay pins. Pins 85 and 86 are the coil primary which is activated by 12 VDC. The normally open contacts of the relay are pins 30 and 87. As it turns out, that relay, and several others are very common relays that are available in standard auto parts stores. I found the relay hanging in the aisle with other wiring and connectors in a AutoZone auto parts store. The 4th picture shows the new relay found at AutoZone. There is a schematic diagram of the relay 12 volt primary pins and the relay normally open control contacts on the packaging of the replacement relay, and it was clear that this was the right relay compared to what the voltmeter told me from examining the pin-outs. I simply installed the new relay into its female socket and everything worked as normal. Macerator control relay repaired. This was an easy repair.

I will also note that there are several other standard automotive style 12 volt relays in our coaches and readily available from an auto parts store. I bought an extra for the "spares" box in the basement.

Gary

[Tim Fox]

Good info to put in the mental toolbox, thanks Gary.

[KennyGolub]

Good to know stuff.


Thanks !!


.

[Gary.Jones]

Oh, forgot, the new relay cost about ~8 bucks and pin "30" is the common relay contact carrying the 12 VDC and 87 is the switched power line going to the macerator motor.

Gary

[gbrash]

I recently replaced the same relay on my 18 Aspire because when I turned the macerator on, it wouldn’t turn off! Had to cut power to the entire coach to get it to stop! Entegra suggested the relay was the issue and it was.

[garysfb]

Great post Gary, saved some of us a lot of investigating if we experience a similar problem. Will be putting a couple relays in my spare parts box soon. Unfortunately, we don't have much else to do right now

[Capt. Steve]

We have had the same issue. I changed the relay and it worked for awhile. Further investigation led to the connector the relay plugs into. Jiggling the wires made the macerator work. The wires at the bottom of the relay connector were not making good contact. I pushed the wires back up into the connector and so far so good. I bought a new relay connector that I will use to replace the old one if it fails again. $14.99 at Advance Auto Parts.

BWD Electrical Connector
Part # PT193

[photraveller]

Gary, great write-up, Thanks !

Steve

[Nowabeachbum]

These do seem to fail a lot! I was at a rally when this happened to me and unable to get to a parts store. So I took a wire and jumped terminal 30 to terminal 87. That bypasses the relay altogether and starts the macerator. I was dumping that way for weeks before I got around to getting a new relay installed. It’s also the way to troubleshoot the relay to confirm it’s bad. I even kept the wire for my “spare”.

[gswindle]

I have been through several. One relay failed and burned/melted the relay harness. It was the orange hot wire. I was able to replace the connector until a final repair is made by Entegra.



Gary

[OldWEB]

Comments point to a weak link in this 40 amp relay. May I suggest a heavier duty relay? 100 amp relay at Amazon.

[Nowabeachbum]

Originally Posted by OldWEB

Comments point to a weak link in this 40 amp relay. May I suggest a heavier duty relay? 100 amp relay at Amazon.

It’s really not that heavy of a circuit. My problem, I think is a cheap Chinese relay. Replaced it with a Bosch.

[GrandPaPat]

Why is there a relay in the circuit at all? The switch and the macerater motor are less than three feet apart. Wouldn’t heavier gauge wire from the switch to the motor have been simpler, cheaper and less prone to failure? But I still will buy some spare relays for the parts bin.
Incidentally, while digging around the wet bay I came across two pairs of wires tucked away that look like they are reserved to power 12v control valves for the black and grey tanks. Stands to reason that Entegra builds one master wiring harness for the big coach lineup just like the autos do for their models and if the option is not included on a specific unit the wires just get tucked away.

[neilnoff]

Gary - Thanks for the write-up and for the good info. Will add relays my list the next time I'm at Auto Zone.