Can I switch on the blower with a switch?

[Scotti8]

I am want to switch on the main blower of the van on while the ignition is switched off, and via a switch in the back of the van. Is this possible?
A little more details: I have my leisure battery in the back, and a switch that switches a 12v fan on and off for when it gets a little warm. What I would really like is to blow in air from the outside without cutting a hole in the roof, and without having to get up and turn the ignition on. Is it possible to switch that main blower on by wiring into it from the leisure battery on a switch? Thanks

 

[Deaky]

I would say this is possible, you could even have a 4 way switch to select different speeds. I think I’d want to use a suitable diode to isolate the two supply’s though. The only issue I can see is that when the ignition is off the heater and recirc flaps might close, unless you have a manual system.

 

[Pete C]

I have no doubt it could be done, but it’s going to be a lot of work.
I haven’t seen this modification done/mentioned on this forum.

Pete

 

[Scotti8]

Thanks for your replies. I did wonder why it has never been mentioned before as far as I could see. I will have a further look into it, and If I manage it I will post an update!

 

[bjzwart]

I stumbled upon this thread because this is exactly what I was planning to do for my campervan conversion. Some companies build in an extra fan, but why adding one if there's already one in the car including a cabin filter!

Is there any progress from the OP?

What I don't get is why it would be a lot of work (if the leisure battery etc. is already there)... Can someone elaborate?

What I wonder is of there will be any fault code when putting diodes in the original wires running to the blower motor.

 

[DXX]

DIY kitchen extractor fan --How I done it --

I tend to use my van for 2-3 days at a time each week, 365 days a year and this time of year condensation is a real issue, especially when cooking on propane which releases moisture as well as any steam from cooking. So I've been looking into active ventilation and was inspired by @TrevorK 's...

www.t6forum.com

 

[bjzwart]

Thanks for the response, but that's not what I'm looking for right now. I want to use the fan that's already under the dash. The only thing needed to be done is to hook it up to the leisure battery probably with a PWM motor controller, so I don't waste energy in heating up resistors.