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Old 01-20-2021, 03:16 AM   #1
Junior Member
Brand: Thor Motor Coach
State: Texas
Posts: 5
THOR #21889
Wiring tank heater for motorhome question

My motorhome is 2019 model of Chateau, black and gray tank doesn’t come with the tank heater. But the have B/G tank heater switch preserved.
I am planning install the heat pads onto black and gray tank, and the pads install was very easy. My question is for wiring, I saw the power control box 12 V section marked #7 fuse for tank heater, the color for the wire is green, then I find green wire behind the power control box and connected onto a relay. Not sure why? The heating pad only require 5 Amps for each, why need relay? And how can I connecting these wires for the heat pads?
Anyone has the diagram for the 2019 model chateau? Also how can I run the wires through behind the cabinet?

Thank you for the helps

Shawn is offline   Reply With Quote
Old 01-20-2021, 03:55 PM   #2
Senior Member
Brand: Thor Motor Coach
Model: Vegas 24.1
State: Washington
Posts: 141
THOR #10717
There is a thermostat installed in the heater pads to not turn on until its cold. Its around 40F or so. Are you testing out the pads below that temp? A infrared thermometer is really helpful to see if they are working.
You can just wire more pads in parallel on the existing pad wires. I also would recommend adding elbow heater pads for the lines.

gte534j is offline   Reply With Quote
Old 01-20-2021, 05:50 PM   #3
Junior Member
Brand: Thor Motor Coach
State: Texas
Posts: 5
THOR #21889
Thank you for the message, Yes these pads are auto on with the build in thermostat, but I still want add the on/off switch onto the pads, since you don't want the pads heat up the empty tank when the temp below 40F. also, the pads and thermostat will using a bit of power from battery, so, I like to add the on/off switch to them, only turn them on during the cold weather.
I really like to use the Thor factory preserved Tank heater opening on the control panel, and fuse pre wired on the power control box, but no diagram to be found, also, look like the tank heater prewired to a relay???
Shawn is offline   Reply With Quote

wire heat pads, wire tank heater.

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