3730 Tank Heaters

[rube191]

Help I have 3 tank heater switches in my control panel none ars marked. I have 2 gray water tanks 1 black water tank and a fresh water tank. Anyone know witch 3 tanks the heaters are for. Thanks

[sourdough]

I believe you will have 1 for black, 1 for fresh and 1 for the 2 grey tanks.

[ChuckS]

At least the tank heaters all have separate built in thermostats. Also with a lot of patience you could use this DC wire color code chart to actually trace the heater wires to each tank

But.. it looks like they use the same color for the wires for each tank heater so it would be a tad more challenging.

https://www.keystonerv.com/media/915...w-wire-doc.pdf

[JRTJH]

Just a comment (my opinion, for what it's worth):

The way Keystone plumbs holding tanks, both gray tanks are going to have water in them as will the black tank. So, I'd suspect that if you're using the trailer plumbing, you will have some liquid in all the tanks, nearly all the time.

The reason for the above comment: If you've got "some liquid in all the tanks" you're going to have all the tank heaters on (if it's going to be that cold) so other than for curiosity sake, what difference does it make which switch turns on which tank heater? Other than troubleshooting problems, you're going to operate them "like they were all tied together" anyway.... At least that's the way I'd operate them.... YMMV

To add "Keystone's varied wiring plans" to the mix, I'd NEVER suspect that any trailer is "wired like the rest in that series" even if they came down the line "one after another and had sequential VIN's"....

[travelin texans]

Originally Posted by JRTJH

Just a comment (my opinion, for what it's worth):

The way Keystone plumbs holding tanks, both gray tanks are going to have water in them as will the black tank. So, I'd suspect that if you're using the trailer plumbing, you will have some liquid in all the tanks, nearly all the time.

The reason for the above comment: If you've got "some liquid in all the tanks" you're going to have all the tank heaters on (if it's going to be that cold) so other than for curiosity sake, what difference does it make which switch turns on which tank heater? Other than troubleshooting problems, you're going to operate them "like they were all tied together" anyway.... At least that's the way I'd operate them.... YMMV

To add "Keystone's varied wiring plans" to the mix, I'd NEVER suspect that any trailer is "wired like the rest in that series" even if they came down the line "one after another and had sequential VIN's"....

Not to mention that because you have switches doesn't necessarily quarntee you have tank heaters.

[ChuckS]

Originally Posted by travelin texans

Not to mention that because you have switches doesn't necessarily quarntee you have tank heaters.

That is a really great point... the switches on many panels are universal and don't necessarily mean the function is installed....

The only way the OP will kow for sure is request from Keystone a build sheet spec by his VIN# or start dropping colorplast to verify with eyes what is actually installed

[MarkEHansen]

The build sheet for my trailed didn't contain any information regarding the tank heaters. I verified mine were "doing something" by watching the DC amperage load on the battery as I turned on each switch.