Fantastic Vent plunger switch electrical shorted out?

[lbdesign]

Can the plunger switch on a Fantastic Vent ever short out?

I have a 2015 model, and the plunger switch that senses the open/close state of the lid routinely needs "exercising" to function. The fan had been acting up lately, requiring me to manually push the plunger switch a few times (with the screen removed) to function again, and i noticed the fan motor was slow to spin up to speed (eg: the fan turned more slowly than it should for a time, then sped up to proper speed).

Today (a weekend), it did not turn on, so I removed the screen, and put my finger on the plunger to push it in, and wow, it was hot enough to fry an egg on, hot enough to burn. Hotter than sunshine would make it. I removed the little fuse in the fan frame to cut off power, and it cooled off. So it was not sunshine. The fuse was intact.

Now I'm afraid to replace the fuse, I'm parked in full sun, and it's hot in here. No tech support from the manufacturer available today.

What would you recommend I do to try to troubleshoot or fix this? I'm not an engineer, but have some tools here. And a can of WD-40. (Though the fan has never been sprayed with anything, just wiping the blades down with a damp rag.)

I've already unplugged the rain senor on the manufacturer's advice, like 2 years ago. That sensor was not well engineered. (I have an external vent hood on to prevent rain leaks).

Thank you in advance.


And apologies if another thread has covered this already -- I searched here and could not find anything.

(keywords for search: fantastic fan, fantastic vent, electrical short, hot switch, wiring, plunger button, lid sensor)

[lbdesign]

I called Dometic support. The agent said there can be nothing wrong with the switch, and the voltage to the fan must be too low. But he said he could not offer help in troubleshooting or in determining where or how to check the voltage. He would not send a new switch.

[Bill M.]

My switch failed. And it locked the cover open. I had to remove the screen and hold the switch plunger to get it closed. And the fan would not run when open. And it went through a period where it ran slow.
A 12 volt switch can certainly fail and many do. The most common failure is burned contacts and that causes heat. I think you need a new switch.

On ours the mobile service truck came and checked the fan and the switch and motor were both bad. He checked prices and avalibilty and opted for a new fan instead. He installed it today. Much quieter than the old one.

The Fantastic Fan used to have a great reputation for customer support. I have heard that Donetic does not send out free parts like the old company apparantly did. Did he refuse to sell you a switch or just did not want to send one free on hope that is the problem?

A good way to trouble shoot would be to remove the switch and jump across the leads. You could meter the voltage there also. This unit did not look easy to access for service. I will go look at it later and see if the switch comes out easily. My neighbor has the old one now to take apart as a learning exercise.

[Bill M.]

The switch is listed on the Dometic parts website for less than $9.00. Be a cheap way to find out. Could be more wrong but the switch sounds fried.

[lbdesign]

Thank you Bill. Yes, I think ultimately the switch will need replacing (or your clever idea of bypassing). Which is the opposite of what the Dometic guy said. I felt the entire conversation he was dead wrong. It really seemed like he was determined to deny any issue, rather like an insurance adjuster. I always take great pains to treat phone agents with courtesy and warmth, because it's a hard job. But this guy was a real challenge.

After that frustrating conversation, I exercised the switch again, replaced the fuse and it worked just fine! So when I'm not using it or not home, I'll unplug it. And I'll call my local mobile repair expert. Sigh. It's so hard to access that I think I'll need a pro, and have it done properly.

[Bill M.]

Maybe the Dometic guy does know what he is about. An inspection of the old fan reveled that it is mostly circuit boards and relays. Power may not go through that switch. A service tech might be a good idea. I opted for another fan with the rain sensor and power opening and the whole installation was $500, so if you can have it fixed or use a cheaper version fan that would be good.

[FC7039]

I too have the same issue with the switch. It rusts. “Exercising it” cleans the connection. Take it out. Either replace it or get to sanding it the best you can.

[lbdesign]

Hey Bill, I think for the switch to function, it must either allow or block power to pass, so there is a current involved. Unless I misunderstand you.

FC7039, yes, I guess it will have to get replaced. I've had others in the past that did OK with "exercising" alone. This is different. it seems. Unfortunately Dometic is less interested in helping with that replacement now that it's bought the Fantastic company.

[Bill M.]

https://edometic.com/allusr/sp.nsf/o...y=BB5RC8A-NNMU

I think it is the dome plunger switch. not shown on the parts diagram when you click on that. I do not know if you can actually buy parts listed on that list or not.

I was recovering from surgery, did not want a project on the roof, and needed ventilation in central Florida. Living in the trailer. I like the new fan just fine. We use it without an additional cover and the rain sensor has worked fine. Hated to replace a 7 year old fan but the mobile tech thought if I was paying him that was the best course of action.

My observations with old Airstreams is that most of the time I cannot find a cheap way out of a problem that actually works.

[lbdesign]

Thanks for the link! Crazy that the switch is not even on the diagram.
I'm glad you got a fan that works.

[flyflinger]

I know I'm late to the thread, but after checking voltage throughout my fan vent, I discovered a short at the plunger switch, which is made of steel and brass.... The steel had corroded, and the rust prevented good contact. So, if you're fan stops working, check the plunger switch first!

Dometic Part number 1122-05, about $8.00 online

[Wayne&Sam]

Originally Posted by flyflinger

I know I'm late to the thread, but after checking voltage throughout my fan vent, I discovered a short at the plunger switch, which is made of steel and brass.... The steel had corroded, and the rust prevented good contact. So, if you're fan stops working, check the plunger switch first!

Dometic Part number 1122-05, about $8.00 online

That would be an open, not a short. Right?

[crazylev]

Very interested in this. My fan lid goes up but the fan does not spin. Was working fine a day before.

Is this something you check or replace inside the trailer or is it up to the roof?

Is there a how to on how to replace plunger switch or at least inspect it? Maybe photos?

I have a 2003 AS with FF model with rain sensor. Hopefully part is still avaible for this. Link above didn’t show the part.

Thanks all

[Bill M.]

Old thread but... I had this problem in one trailer and posted a couple of times and now I seem to have it in my other trailer. The fan just won't open. Found one "in stock" at a company and ordered it. Apparently Fed x lost it? Just got my refund today. Not many of these fans available now. Maybe I will mess with the switch again to see if that is the problem. Maybe it is time to switch to max air or maybe just wait until next year and hope the fans become available again.

[Baby Zeppelin]

Mine did that some time ago. Found that if I removed the screen I could reach the plunger switch and snap it in and out a few times. Has worked fine since. Apparently contacts just get high resistance, need cleaning.

[Bill M.]

Found a new fan in stock on Amazon. I am doing the $350 repair for whatever $8.00 part is actually broken. Most Airstreamers will probably understand. We have been having intermittent trouble with the fan for a while. We rely on that fan a whole lot. Another Covid project for the fall, I guess.

[crazylev]

Thats guys.

Baby Zepplin. Can you describe where that plunger is? I had my screen off but didn’t see anything that looked like a plunger switch. I’m probably not looking in the right place.

Thanks again

[Bill M.]

Plunger switch is towards the hinged sided of the cover facing up on the top of the unit under the cover. You can take the screen off and see it and access it with your finger.

[crazylev]

This week i removed the screen to try and locate the plunger switch you guys mentioned. I just was not able to locate it. Now Im thinking that this is something i need to find when I go up on the roof to seal stuff in the spring.

Do you guys know if it is possible to remove fan assembly from inside the AS? Or is that also done on the roof? That would sure make things essier.

I removed the square “trim” in the trailer and didn’t see how to do this. I should really give fantastic a call too.