removing VERY old Jensen vent fan

[Deb Mac]

I have a nasty old Jensen fan in the bathroom - you know the one - tiny little plastic fan, so old the blades snap off in your hand? I have a Hengs Vortex to pop into it's place, except I am having problems with getting the old one out. All of the pictures and videos I see, the old fan has a push button switch at the side, coming through the "garnish" (love that word)..

This has an entire box, with a toggle switch that came straight down through the screen (I had to rip the screen in order to get it off since the nuts on the switch are rusted) and the switch box (likely some kind of junction box - can't tell, have to break into it) is what I assume is spot welded to the crossbar, since I can't find any screws or bolts that come through the crossbar. And.... the crossbar is also not particularly sturdy. Of course, the crossbar is essential since that is where the gear mechanism lives to crank up the hatch

My options appear to be - just rip off the cross-member and replace it (if that is even possible) - that would get rid of the old motor and the old switch/junction box, or try to pry the box free of the crossmember and hope that once it is out of the way, I can stabilize that crossmember with a couple of self-tapping screws. That is my first go-to. I really don't want to have to try to replace the entire cranking mechanism.

Has anyone had to deal with this particular old Jensen fan? And how did you go about it? Or did you just bite the bullet and replace the entire assembly. I really didn't want to get into the expense of a fantastic fan or maxxair for a bathroom fan. And to replace an obsolete fan/vent assembly with exactly the same thing didn't seem like much of a step up.

[John in Michigan]

I would remove the entire assembly. It is likely riveted into the roof. Then install a new Hengs assembly through the roof using lots of butyl tape and fastening with either waterproof rivets or stainless steel screws.

You should remove the entire assembly and re-seal it anyway, if you haven't already done this. This is a prime source of leaks after 40 years.

[John in Michigan]

The cross bar is welded in, thus providing a water-tight barrier between the vent frame and the roof core.

[John in Michigan]

There may be another problem with using the Jensen vent frame. I happen to have a Hengs vent frame and a Ventline vent frame. The hand crank is not in the same location when comparing these two brands, so I am wondering if Jensen vent frame and the Hengs Vortex fan are compatible, i.e., crank in the same location. Did you check this?

[John in Michigan]

OK the Vortex fan description indicates that it works with Hengs, Ventline, Jensen and Elixir powered vents so you could try to re-use the vent frame.

I would remove the assembly from the trailer, then determine how to remove the fan and the electrical box. They might be welded to the cross bar.

[Deb Mac]

Thanks for the comments. It seems the cross bar is spot welded onto the frame but loose. And the junction/switch box is also welded on. So I do doubt that I could safely/effectively remove anything from that bar and leave anything intact.

I’ve been searching and found someone nearby that pulled their roof vent to install a fantastic fan. It’s in very good shape so I’m off to pick it up tomorrow. Saves about $50 at my end. And although the vent was resealed a couple of years ago by the PO (dry as a bone in there and no sign of water) it’s still more likely than not that I’ll have to put a whole new vent in. But I’ll play with it first, simply because I must!!

[Alex Adams]

Not sure how involved you want to get, but you might be able to drill out the spot welds holding the cross member to the vent frame so you can remove the cross member. Then you could drill out the spot welds on the bracket. Replace the cross member and use stainless steel bolts to attach it back onto the frame. Be sure to use some sort of lock washer or Loctite like compound on the nut so it won't vibrate loose.

[Deb Mac]

That's my plan 1. I can't see it being a whole lot more work than trying to remove the old frame. I have the pulled vent from another trailer - just picked it up. It is in very good shape, from a much newer trailer than mine! For $30 couldn't go wrong. $10 in gas but still....

Since the old one is still very much water tight, and the butyl around it is in good shape, (PO did do it 2 years ago - found the receipts for the materials) rather than start by pulling that one out completely (that will be a tonne of work on it's own) I might take a look at removing the original cross-member and the entire assembly with the exception of the metal frame and replacing it with the assembly from the one I just picked up. The cross-bar is already rotating slightly along the long axis - it may have been removed at one point and just screwed back into place. I'll climb up there this afternoon (if it doesn't rain) and take a look. Looks like it could be more or less plug n play - sizing of these things is pretty universal.

[Deb Mac]

Well I removed the old cross-member and took all of the little extensions off of it using my little dremel tool and a grinding wheel - the junction/switch box, motor mount tab, etc. Cleaned it up and put it back in with a couple of metal screws and lock nuts. I also applied a little loctite just for good measure.

Pretended i was hanging a ceiling fan by myself, and used some old 8 gauge wire left over from when I moved the new battery inside as a hanger. Wiring was easy, puttering with little philips screws and a non-magnetic screw-driver not so much. But after dropping screws on the floor several times (I had covered the floor drain with a mat and plugged the sink!) got everything lined up, screwed into place and I finally have one project that is COMPLETELY finished. I have 4 or 5 others that all depend on getting the previous one to a certain point before I continue, and then you find something else you have to do first, and so on.

But it is nice to be able to put that one to bed!

[Deb Mac]

And I didn't need the vent that I picked up yesterday for 30 bucks. But, it's always nice to have a spare. I have a "spares" box in the garage that is rapidly filling.