reverse engineer New Model Fan-tastic fan rain sensor?

[jage]

My old 3-speed, temperature sensing, rain sensing fantastic fan was so great I bought the exact replacement model. The problem is they redesigned the rain sensor. The old model closed with moisture and opened when the sensor dried. In practical terms this meant a light sprinkle might close the fan for 10 minutes, a heavy rain for an hour, at which point the fan opens and if it's still raining it closes again.

Pretty brilliant and my absolute favorite feature of the fan, since it's our only cooling source.

The new fan looks the same except when the slightest bit of moisture gets on the rain sensor it just closes forever. 11pm, 3am, the fan doesn't come on again until you get up and flip the switch (I purposefully and intentionally avoided the remote control).

I emailed fan-tastic about the problem and they basically said "we changed the design".

So now I'm stuck with a brand new, freshly mounted fan-tastic vent that I need to reverse engineer to be like the old one. The worst part is I gave my old fan away because someone with a base model wanted to upgrade the sensors etc.

So- does anyone know how to reverse this design flaw and have it reopen automatically after the sensor dries?

Is there wiring I can change or a component to swap? Which part of the fan controls this behavior? I know I can swap parts with an older model (if I can find one) I just need to know which part/parts to look for.

Obviously if I can soldier, jump or wire something differently that would be easier.

Please let me know any ideas on un-fixing this vent fan!

[jage]

Thanks for all the replies. My fan is above the cab in my van, and the re-designed model is already too tall- it sticks up 2-3" before the cover, whereas the old cover was attached to the flange that goes into the roof.

However I figured out how to solve all my problems with the new fan (it also seems weak compared to my old one- like you can't tell if it's blowing in or out by feel right next to the fan...)

In any case the solution is I bought a 6000RBTA "obsolete" model on eBay. It sits flush, has the old black motor and best of all the rain sensor is "broken" so it will open and close and open again!

Now all I have to do is tear out the otherwise new 803350 and redo my whole install. Good times.

Thanks again for all the messages and suggestions!

[aruba5er]

Mine never closed when it rained and co. sent new sensor. Then it closed so fast is was like your warm breath on the sensor. I gave up and put a Max air cover over it and have been satisfied since. some tech we don't need. No more wet bedding.

[hypoxia]

Fantastic Vent told me they redesigned it due to complaints that the lid kept going up & down. The circuit board is what changed.
I like the old style, when I leave the camper for the day I don't want to come back to a hot house just because of a rain shower that occurred 10 hours ago. When I'm in the camper and it runs up & down I can turn it off if I don't want to hear it.

[ScottG]

Yep, thier warranty went down the toilet and the new design motors are louder too.
I have one of each in my RV and the differnce is staggering.

[GordonThree]

I could program you a new brain, even add WiFi control if interested, just need a fan to work on for a few months.

Adding a WiFi brain to my Vortex fan right now, no rain sensor since it's under a cover. The brain will just handle timer, thermostat and fan speed. Also adding a WiFi brain to my Fantastic Endless Breeze - that one's a bit tricky, as large as the housing is, there's not really much extra room inside it for a brain.

[dougrainer]

The Rain sensor is about the same. Just looks a little different. ALL the sensor does is send a signal to the control board and then the control board does all the thinking. So, you would have to figure out the control board logic. As to why they did the change- probably because some people complained or sued because the re open feature probably caused a lot of water to come in and they blamed Fantastic. They usually only change design parameters when they have been sued or enough people complain. Especially the OEM RV makers that had to respond to customers complaints. Doug

[Chris_Bryant]

FWIW, Fantastic Vent was purchased by Atwood who in turn was purchased by Dometic.
Does the new sensor look the same?

[Champ198]

Can you add the fan control to a thermostat that would power the fan back on at a set temp? The fan might get caught in loop if its raining and hot inside. I also like the idea of a vent cover to protect the fan from rain to keep the sensors from going off.

[GordonThree]

Can you post up some pictures of the circuit boards 'n such?

I'm guessing the rain sensor works the same way it always has, just they changed the programming in the brain of the unit, changing how it responds to the sensor being triggered.

From an engineering standpoint, the new method is what I'd choose - I'm surprised to learn the old way could have the fan opening and closing repeatedly and frequently, hard on the motors.

rjxj's suggestion of a vent cover is the best solution. With a cover, you can keep circulating air even if it's raining.

[azrving]

Could you use a vent cover? I installed mine 2 1/2 years ago and used a cover so never dealt with that issue. I know the customer service isn't that great. I called about an issue with the remote control plastic mount not holding the remote tight enough and the woman told me "What? Do you expect it to be perfect? " Ahhh OK

[MrWizard]

I don't have either version, I have Max Air fan
But you got me thinking
This switch, do you mean the on off switch, a membrane push button monetary contact on a circuit board

Maybe a timer circuit powered from the fan input 12v with a signal sensor on the motor wires
When motor stops the timer starts, when it times out it momentarily closes the switch circuit

Just a thought, I don't have that fan, so I can't prototype the idea to a working model

Or if you can identify all the components on the circuit board you can enter them into a circuit design program and play around with the design yourself
There are free programs for this, for PC and android

[rk911]

jage wrote:
My old 3-speed, temperature sensing, rain sensing fantastic fan was so great I bought the exact replacement model. The problem is they redesigned the rain sensor. The old model closed with moisture and opened when the sensor dried. In practical terms this meant a light sprinkle might close the fan for 10 minutes, a heavy rain for an hour, at which point the fan opens and if it's still raining it closes again.

Pretty brilliant and my absolute favorite feature of the fan, since it's our only cooling source.

The new fan looks the same except when the slightest bit of moisture gets on the rain sensor it just closes forever. 11pm, 3am, the fan doesn't come on again until you get up and flip the switch (I purposefully and intentionally avoided the remote control).

I emailed fan-tastic about the problem and they basically said "we changed the design".

So now I'm stuck with a brand new, freshly mounted fan-tastic vent that I need to reverse engineer to be like the old one. The worst part is I gave my old fan away because someone with a base model wanted to upgrade the sensors etc.

So- does anyone know how to reverse this design flaw and have it reopen automatically after the sensor dries?

Is there wiring I can change or a component to swap? Which part of the fan controls this behavior? I know I can swap parts with an older model (if I can find one) I just need to know which part/parts to look for.

Obviously if I can soldier, jump or wire something differently that would be easier.

Please let me know any ideas on un-fixing this vent fan!

I have the same issue. Fantastic Fan was sold to another outfit a while back and they changed the design not the original company. if enough of us complain a change might occur.