Adding a Wireless Remote Control to the Macerator

Dumping the holding tanks with Roadtrek macerator system is pretty easy and quick, although the switch location which activates the macerator pump is not very ideal. The switch is located on the frame of the driver seat facing the driver side door. To operate the macerator you have to open the driver side door and reach for the red switch, and since it is momentary switch you have to hold the switch the entire dumping process. It is a minor inconvenience, but leaving the driver side door open while dumping the holding tanks is an open invitation for flies/ bugs to get in the RV not to mention when it is raining...I thought, there could be a better solution.

At first I thought of replacing the momentary switch with an on/off rocker switch, but someone could accidentally flip the switch on and run the macerator dry causing early macerator failure. RT used a momentary switch there for a reason.

My solution is a wireless on/off momentary switch. Again I decided to go with a momentary switch on the wireless controller as for the above reason.  The wireless controller and remote transmit/receives analog signals which is prone to radio wave interferences that could inadvertently activate the controller. Although I am using a separate switch to power the wireless controller, there is always a chance of forgetting to turn it off.

I got the wireless remote switch from EBay. I've seen Amazon carries them but it is a different brand. Wireless momentary switches. I bought the less expensive controller with a lower load rating internal relay and used an external heavy duty automotive relay instead as pictured below. It would be easier and cheaper to replace the external relay if it fails. An inline fuse is needed for safety as you are tapping power from the 25-amp fused line.

UPDATE: I have replaced the wireless momentary switch to a basic On-Off switch relay, I got tired of holding the momentary switch to On position while dumping, lol. The replacement remote switch also has built in 40-amp rated relay so no need for external relay, much simpler to install.
Wireless Remote Switch with 40-Amp relay.

New On-Off Remote switch wiring diagram

Older wiring diagram with momentary remote switch and relay

wiring harness with spade connectors

First, you have to find the live (+)12 volt wire that goes into the factory switch using a multimeter then label each wire for easy identification later. Note: disconnect the coach battery before proceeding below for safety.
 The wireless controller was mounted under the driver seat where the fuses are located. I temporarily unscrewed the top row fuse holder for easier access inside the fuse compartment. All you have to do is plug the wiring harness to the right connectors then run the power wires for the wireless controller to the switch location of choice. The ground wire was tapped into the metal seat base as pictured below.

 

 The wires (3 wires/ with ground wire for switch illumination) was routed into the driver side B-pillar into the overhead driver side cabinet. You need to remove the driver side foot well plastic covering and the B-pillar trim to run the wires to the switch location.

 Inside view of the B-pillar plastic trim cover; note that Roadtrek has a lot of wire runs on this area.

It was hard convincing myself to make holes into the cab overhead cabinet for the switches. But when I got the hang of it, I decided to install more switches (battery power/ generator/ cell booster/ and Wi-Fi booster switches) on this location for convenience. On the inside of the cab overhead cabinet, there is a factory cover for all the wirings that feeds the speaker and the overhead light, make sure that the holes you make will be inside the wire cover.

2 switches down, 3 to go.

These are now my favorite switches in the RV, esp. the battery power switch and generator switch. When refueling and you needed to turn the fridge off, just hit the battery switch and it's off, turn it back on and fridge resumes where it lefts. The generator switch is handy when you want to start the AC when driving, passengers in the back does not have to unbuckle and get up to start the gen set, it's really handy. Of course, I also like the switches for the Cell and Wi-Fi booster, who would not like that? Details would be on my next posts.

Back to the macerator switch...to dump the holding tanks all I need to do is turn the switch on to power the wireless controller, hook the discharge hose, open the waste valve and use the remote control to run the macerator. I can even walk around the RV while engaging the remote and it works flawlessly. Added benefit is how easy it is now to discharge the gray tank while showering on a full hook up sites, no need to blindly reach out for the factory switch, although the factory switch is still operational as a backup.