[Templeton]

I am curious, is a hack like this easily possible on the gen4?
Saw this on youtube:

If the sienna is completely shut down, and one runs independent positive and negative wires to the OE cabin ventilation blower fan directly (so bypassing any pc boards, running the wires directly to the blower), and then run those wires with a motor controller to a 12v output from a portable battery (like a jackery), would it be possible to have fresh air come in the van when it is shut down? This would, of course, be without heat or A/C, it would just be to pull in some fresh air. Then, when ready to power up the sienna and drive, one could fully disconnect the new wires to the blower to prevent any electrical conflicts. Is this a doable mod or hack? If not, what are the issues that would prevent such a mod?

 

[jareza]

I would not advise to do this sort of thing on newer generations vehicles (not just toyota) the video you quote is doing this mod on a very old utility van.
A ton of things come to mind by doing this mod to a sienna (current backflow ie). Newer components also carry a can bus wire, that works with minimal voltage to communicate with the car... you don't want to mess with that network

A ton of people use hybrids for camping since they can turn on the car for a certain period of time and the car will cool the cabin without the use of the combustion engine.

 

[Templeton]

I would not advise to do this sort of thing on newer generations vehicles (not just toyota) the video you quote is doing this mod on a very old utility van.
A ton of things come to mind by doing this mod to a sienna (current backflow ie). Newer components also carry a can bus wire, that works with minimal voltage to communicate with the car... you don't want to mess with that network

A ton of people use hybrids for camping since they can turn on the car for a certain period of time and the car will cool the cabin without the use of the combustion engine.

Thanks for the input. But if l connect the external power only to the blower motor itself, and run the blower only when the van is fully powered off, and if l completely disconnect the external power source (using an anderson type connector) when the van is on or running, wouldn’t that solve all of the issues you bring up? Or, if no, what am l missing?

 

[jseyfert3]

This is great. I don't have a 4th gen, but I want to do exactly this with my current van once I have a camper van, which will have rooftop solar. In fact, I've wanted to have a solar panel to do this for a long time. I thought it would be great to have a solar panel run the HVAC blower bringing in fresh air when parked, to make the inside smell better, and more importantly, so it doesn't turn into an oven in the summer.

My plan was essentially the same, with an ignition switched relay that would disconnect the blower motor from the vehicle, so that a solar panel and controller could run the fan if the sun was shining, without touching or draining the vehicle battery. I also figured, depending on where (or if) the 3rd gen Sienna defaults the vents, I could hack into the fresh/recirc air dampers and mode dampers and make sure those are set the way I want automatically. Which may, ironically, involve tapping into and sending commands on the very CANbus network that @jareza said not to touch. 😂 HOWEVER, on a serious note, do NOT touch the CANbus unless you really know what you're doing. I, somewhat unluckily, got a crash course in CANbus this summer at work, so I'm now decently familiar with the basics of how it works and common ways it can fail.

If you don't need to touch any of the air dampers, then isolating the main blower with a relay as he describes at the 15:00 mark will let you run the blower without worry of damaging anything (if wired properly) or interfering with the CANbus network.

 

[DKH]

You could just leave your car in ON mode, set the temp to something lower than ambient, and turn off the A/C.

I use 12v fans in the rear window connected to a Jackery and a battery powered fan.

 

[Chubbysumo]

Thanks for the input. But if l connect the external power only to the blower motor itself, and run the blower only when the van is fully powered off, and if l completely disconnect the external power source (using an anderson type connector) when the van is on or running, wouldn’t that solve all of the issues you bring up? Or, if no, what am l missing?

The issue becomes what is common grounded with the blower motor? If you're applying power on the power side of the blower motor, what else is getting power because it shares a common ground. Current back feeding is very bad for circuit boards. I also believe that when you turn the van off, it closes the blend doors, and the vent to outside so it's not pulling air from outside anymore.

 

[Templeton]

You could just leave your car in ON mode, set the temp to something lower than ambient, and turn off the A/C.

I use 12v fans in the rear window connected to a Jackery and a battery powered fan.

Yes, that seems most simple (and thanks for the pm on this as well). But that leaves a problem with how to get reliable airflow in bad weather. And how to get airflow with maximum stealth. And leaving the van in 'ready' mode works too, but then the van is starting up every so often to top off the batteries. I wish there was a simple way to get an reliable airway into the van even in really bad weather ...