Fantastic vent fan

[Dale Malquist]

Original Fantastic vents in the Contessa motor home. Lift motor in bathroom fan will not shut off. Vent cover is up and the lift motor keeps running and has stripped it's connection to the lift are mechanism. Can't find a replacement printed circuit board which I suspect as the problem.

[Bill Lampkin]

Have you tested the pin switch on the cover base? You'll have to take the screen off so you can get your hand up there to push the pin down-fan off of course. The cover closes against this pin switch which then shuts off the cover motor.

[Bill Lampkin]

As for parts, try

https://www.etrailer.com/dept-pg-Accessories_and_Parts-pm-Fantastic_Vent.aspx?gclid=CjwKCAiAhbeCBhBcEiwAkv2cY3u3MDzdPrhrcXgK9edlAh7JqmvuEPsSfeSlt-u_BnSPTdETV5JKShoCDzEQAvD_BwE

Back before they were swallowed up by Atwood (now by Dometic, I think), you could just call Fantastic Fan and they would send out replacement parts, gratis. I never had such good customer service from an RV supplier as I had on more than one occasion from Fantastic Fan.

[Bill Lampkin]

Exploded view parts diagram:

https://pdxrvwholesale.com/p/fantastic-exploded-part

[Frank Bergamo]

Dale,

Is the manual crank knob pushed up and engaged? Push up on the knob to engage motor gear, pull down on knob to manually open lid. Hope this helps.

[Joel Ashley]

If the gear is stripped and the cover up, he may not be able to lower the lid manually either.  The gear was probably stripped first and that kept the motor from locking out, not a circuit board failure causing the strip.  This is arguably  the most common failure for these vents.  The original mfr., as Bill noted, used to send replacement parts, cleaner and grease, and instructions free, but that went down the tube years ago upon sale of the company to the conglomerate.

The last time I replaced the gear assembly I had to work from both the inside and the roof.  The primary cause of the stripped gear is a lid that was shut tight for the winter or other long storage/lack of use.  Sticky gummy roof dirt, heated, maybe frozen, and thawed cyclically, adhered the lid edges to the roof enough that the initial lift angle applied minimal force to the lift arm and maximum stress to the gear.  The last arm or gear assembly I was sent by Dometic had a simple design modification to an engagement stop that made it less susceptible to problems.

The best preventive steps include getting on the roof at least yearly and cleaning the lid edges and the area of the roof where the edges seat.  Simple Green works fine for this.  Then rub into the cleaned, rinsed, and dried edges and roof seat a dry silicone Teflon product to fight the stickiness issue.  303 Protectant is good also, because of its UV resistance.  A little silicone or silicone grease on the gear and arm won’t hurt while you’re at it.  If you wash your roof regularly, this is your opportunity to take care of it.   

Then most importantly, practice good operation technique:  after closing the lid for coach storage, pull the knob down and manually crank the lid back up just a smidge, so it’s not pressing down so tightly on the roof.

https://www.lowes.com/pd/Oatey-Silicone-Grease/50236505?cm_mmc=shp-_-c-_-prd-_-plb-_-google-_-lia-_-142-_-plumbingconnectionsandsupport-_-50236505-_-0&placeholder=null&ds_rl=1286981&gclid=CjwKCAiAhbeCBhBcEiwAkv2cYyoglvpmxSsbmJXtJpLcOJ7PApHM4OhwY68OpRxmQ_T7KKEJAgbBhBoCcYYQAvD_BwE&gclsrc=aw.ds

https://www.acehardware.com/departments/plumbing/plumbing-tools/plumbing-grease/4768503?store=07110&utm_source=google&utm_medium=cpc&gclid=CjwKCAiAhbeCBhBcEiwAkv2cY77A7pdyKq0xRCnV6lmfpGo81Z7N-QG7Ay5t206bpAljfjmGzFUJOhoCX4IQAvD_BwE&gclsrc=aw.ds

Just my experienced 2 cents.
Joel

[Scott Shearer]

Dale,

The controller must sense an increase in current (i.e., the vent lid has reached its limit of travel) before it will shut off the lift motor. If the lift mechanism splines are stripped the motor will continue to run.

All three of our Fantastic Vents stripped the coupler between the lift motor and the lift arm for the very reason that Joel mentioned.

Fantastic offers upgrade kits that provide a significant improvement over the OEM, I upgraded two of our vents with the “non-remote” kits. However, when it was time to upgrade the third vent, I discovered that only the remote-controlled version was available (at least when I was looking). I’m not sure that I want the remote-controlled version.

The coupler is pressed onto the lift motor shaft so if the splines on the lift arm are still intact, for about $5.00 and an hours’ worth of time you can make a new coupler and have a functioning vent. I did this with our third fan when I found out that the manual upgrade kit was not available. This won’t work if the splines on the lift arm are also stripped.

Purchase a splined long shaft (1 3/4”) RV window crank handle, found in most RV parts stores for about $5.00.

1 Using a hammer and drift, remove the damage coupler from the motor shaft.
2 Cut the splined end of the window crank handle to the same length as the original coupler.
3 Drill out the non-splined end of your ‘new’ coupler using a drill bit that slightly smaller than the diameter of the motor shaft
   (use the original coupler as a gage for the drill bit).
4 Using a vice, press the new coupler onto the motor shaft.

I ended up installing vent covers on all three vents. In addition to being able to use the vents when it’s raining, they significantly help with the sticking vent lid issue.

[Gene Obie]

I had similar problem i was able to fix last week by replacing the lift arm. https://www.amazon.com/gp/product/B00LNKURQS/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

My symptoms were vent would usually close but keep running and would need just to turn power off. If I pulled the knob for manual mode it would eventually catch if I turned it many times and I could open and close manual mode. I thought maybe motor gears were stripped. Previous owner had spare motor assembly - I replaced that with same result so came to conclusion the spines on the lift arm were bad. I replace the lift arm (easy job) and that fixed it for me.

[Gene Obie]

Just an update on stripped fantastic fan gear shafts. Replacing the arm per my previous post (long time ago) didn't work that long for me as it stripped out again after short period of time. The barrel coupler attached to the motor was stripped as others have mentioned. Here's a mod I made that's worked well twice now. I basically replaced the geared attachment with a pin and slot by drilling through the bottom gear coupler with a small drill bit, cutting off the bit with a dremel creating a pin, and putting small dab of JB weld on each side of the barrel to keep the pin in place. See attached photo. I then cut a slot with dremel cuttoff wheel in the mating gear assembly to match up with the pin. The pin/slot arrangement allows removal of the motor from the arm, similar to OEM gear solution, and still allow the connection to "float" and not be too rigid. The first fan has lasted about 2 yrs with  no issue so I just did the 2nd fan that failed recently and it's now working great. Takes a little time but much less time and money then replacing the entire assembly.