Heller fans slowing to a stop!

[S Y Tuppenny]

Hi, hope I'm in the right place!
I have some heller 12v fans on board and a few have suddenly stopped working. The thing is that if I apply a little bit of pressure at the back of the blades, they will go again, too much pressure and they stop.

I am wondering if anyone else has had this problem and if anyone knows what I can do to fix them please. Throwing away and buying new are not an option for me. I need a fix.

Thanks for your help
Gillie,
S y Tuppenny, Malaysia

[Alan Mighty]

Contact Us - Hella Marine

[brianlara 3]

From a distance, this tradesman suspects voltage drop. If it were only one fan the it could be anything.
My suspicion is that the fan furthest from the supply failed first.
Use a multimeter to check voltage and the check for resistance in the earth return.
Irrespective of the distance the earth wire from the unit back to earth must have absolute continuity, virtully no resistance.
But i susp voltage drop in the joints (which I always solder)....or very little voltage even at switch on your switchboard.
If you dont have a multimeter, they're cheap, come with instructions and solve many many problems.

[brianlara 3]

Forgot.... very ofter older wire, especiall untinned wire, just corrodes away to a spaghetti of copper oxide which just ain't wire anymore...just brown powder in a pvc tube.

[KadeyKrogen38]

Heller fans wear out after about 2000 hours and are trash at that point

[Seighlor]

I've experienced similar problems with several fans. Though not Heller, my guess is a good cleaning and a bit of light lube oil applied to the shaft may get them working. In my case, I removed the protective covers and cleaned the blades and motor housing with a soft brush to remove the accumulated dust. Then applied a drop of light lube oil to the shaft at the motor housing. And they worked like new.

Hope this helps.

[doug cusick]

have had these for years...when they get old the internal components in the motor wear out...sorry mate there is no fix it's new fan time!

[Jason Flare]

So, I can safely assume we are not going to be talking about DC v. Heller?

[UNCIVILIZED]

Originally Posted by Seighlor

I've experienced similar problems with several fans. Though not Heller, my guess is a good cleaning and a bit of light lube oil applied to the shaft may get them working. In my case, I removed the protective covers and cleaned the blades and motor housing with a soft brush to remove the accumulated dust. Then applied a drop of light lube oil to the shaft at the motor housing. And they worked like new.

Hope this helps.

This is worth trying. Though inspect around their hubs with the blades off, prior to starting anything along these lines. And BTW, have you tried seeing if they'll spin without the blades on the hubs? Never hurts to inspect them nekked too.

Often, over time, bits of dust get compacted around the motors' axle where it exits, & it binds things up a bit. Along with causing wear in said location. Even to the point of penetrating sealed bearings & motors, or if not penetrating them, then gumming them up.

So after cleaning this area, I'd try some ("dry") graphite lube first. With machine oil being the #2 choice. Since dry lubes won't attract more dust & garbage to the area like an oil might. Just use caution when cleaning, as things like dental picks, which have sharp tips, can at times damage things with tight tolerances, & especially, seals.

On many things, I've used brake cleaner with the straw attached to the can to blast gunk out of things. But it too is a risk, as it has some strong solvents, which (rarely) can attack plastics, rubber, or some seals materials. It's generally handy stuff though. And it degreases too.

[Dave_S]

One possibility is that the thrust washer or surface has worn out. Not sure if you can get to it to fix it or not. If not some light lubricant on the face might help short term. But if the armature can move further back because of wear and is now in contact with another part or is no longer in good contact with the poles or brushes somehow you need to move the armature back by packing out the thrust face.

[rwidman]

Originally Posted by Seighlor

I've experienced similar problems with several fans. Though not Heller, my guess is a good cleaning and a bit of light lube oil applied to the shaft may get them working. In my case, I removed the protective covers and cleaned the blades and motor housing with a soft brush to remove the accumulated dust. Then applied a drop of light lube oil to the shaft at the motor housing. And they worked like new.

Hope this helps.

This is worth a try. There should be a bearing at each end of the motor so try to oil both. Cleaning before oiling is the best plan. And you want light oil, not motor oil.

[GalleyHo]

Is your fan the single speed Hella with a dome-shaped switch on the front?

Bill

[S Y Tuppenny]

not sure what you mean tbh! but thanks anyway

[JPA Cate]

S Y Tupenny,

Tbh, I don't have a clue what you mean, either! It might help if you mentioned the person's screen name or even the post number.

The general idea is as follows:

Demount one of the fans. Remove the blades from the output shaft. Visually check to see that the area by the bearing (inner visible end of shaft) doesn't have dust, hair, or anything else spun onto it. Clear it, (a dental pick is great for this, if you have an appropriate one)* and clean it with meths. Place one or two drops light machine oil on the base of the shaft by the bearing, and hand spin the shaft to spread the oil. Me, I'd use sewing machine oil, 'cause that's what I have. Clean all the exterior bits, and give it a go.

* We are tool using animals, possibly you can make a probe from a paper clip, or a round toothpick.

It is always possible that they have worn out, and it's a real pain to re-brush the motors, although for a while, years ago, slot car drive motors were being used for the purpose in the cruising fleet. If worn out, you can replace with Caframo, which are not nearly as difficult to keep clean.

Try with each of the fans, because generally some of them get more use than others, and will be farther along their self-destruct path.

Now, since you're de-mounting them, go back and re-read brianlara3's posts about dealing with the possibility of the wiring starting to fail. Wire failure is common on boats.. Check the wire, before you go to tighten it, make sure it's pretty much intact.

You can do this.

Ann

[senormechanico]

I REALLY like these. Quiet, move lots of air and have liquid bearings:

Arctic Cooling F12 120mm 1350 RPM Fan AFACO-12000-GBA01 | eBay

Hall effect sensor instead of brushes, so nothing to wear out.