Heater fan motor dying?

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Hey All,
as we head from frigid Chicago up to even colder South Dakota for a couple of shows, my front heat exchanger stopped working. This is the unit attached to the webasto heated liquid. (Sorry, I know, my terminology stinks!) Last night I noticed that the fan was struggling. Then, I noticed it started to smell like a motor that was burning out (or, trying to spin, but meeting with sufficient resistance that it was overheating.) Well, this morning, it won’t spin the little turbines at all. Well, actually, it will if I put on the 24 volt option instead of the 12 volt. But even with 24 volts, it struggles to get moving and never spins fast more than a few rotations. When I try to spin it by hand, it will move, but has a constant drag on it. (not sure if that is normal or not.)

So, this looks difficult to pull out. It is attached to the coolant lines and jammed into the front/passenger dash area. I see that I could probably pinch off both hoses, make a huge mess, take the hose clamps off the lines, and take out the whole unit. What do I need to fix though? It is getting plenty of heat. The fan just don’t spin. Bearing? Motor? Whole unit?

I am on the north side of suburban chicago. (drove by Liberty by accident the other day! exciting 🙂 I’m headed up to MN, then over the SD later this week. But for now, I’m enjoying my relatives and old friends… and now, fixing, the bus:-)

Any thoughts what I should do?

Thanks,

Adam

[MyPrevost]

Adam,
Our bus had a fan blade hitting the mounting housing on the front heat exchanger, it was annoying and only hit when the fan was starting up. With the trim panel removed I could get to the heat exchanger and with a flash light and mirror could see the mounting screws in the back of the unit, ours is screwed on top of the dash heat/air plenum, with the mounting screws out (it took a varity of screw drivers) I could move the heat exchanger around enough to get to the fans, this one has two. Our problem was how the fans had be mounted and we fixed them without replacememt, but I had them out.
The point is I did this with the water lines still connected, no mess. Our unit is a Aqua Hot and the heat exchangers were made by some other outfit and I don’t remember the name. You may be able to do the same thing and replace your fans. Our fans looked like something you could get at Granger.

[MyPrevost]

Adam

If you need help give our own POG member Joe Cannarozzi a call. He is in Chicago. His phone numbers are on Dale’s Map listed under Quick Links. Joe knows his way around a bus and is close to you.

[MyPrevost]

Ditto that. Joe has done work for me and would be your best bet- if he is available.

Tully

[MyPrevost]

Thanks! Talked to Joe and we agree that with Marathon willing to ship me a new fan motor for $135.00, it was kind of a no brainer. Its on the the way and I’ll install it tomorrow before we head to South Dakota for our shows.

Thanks for the input. Anybody change one of these motors lately?

Adam

[MyPrevost]

Adam,

Mango Mike replaced one and documented the process on his website. Check out http://www.prevoman.com/Pages/Webast…wer/page1.html .

I have not tackled the project yet, but I do have a fan rattling on my front heater, so it only a matter of time. Let us know how it goes.

Hector

[MyPrevost]

Adam when will you have that motor and where will you be when you get it. I can shoot up to you. What kind of a window do you have after you get till you have to roll?

Hector, Mango replaced a prevo blower motor, Adam needs the one for his Webasto.

[MyPrevost]

Adam when will you have that motor and where will you be when you get it. I can shoot up to you. What kind of a window do you have after you get till you have to roll?

Hector, Mango replaced a prevo blower motor, Adam needs the one for his Webasto.

Joe, I should have the motor by tomorrow evening. I may try to tackle the project on my way up to Sioux Falls. As I see it, the colder the temperatures outside, the faster I’ll get ‘er fixed. I appreciate your willingness to come find me, but I fear that I may be hard to pin down. If for some reason I end up sitting put on Thursday, I’ll give you a ring and we can see about getting together. Thanks for your help on the phone to day.

And, by the way, Hector was right. Mango did replace the webasto exchanger motor. The only difference is that my is made by frigid cool, not red dot.

Thanks again,
Adam

[MyPrevost]

It will be the First of March, end of the week

[MyPrevost]

Adam,

Any words of wisdom on what to do or what not to do when changing our a Wabasto blower motor?

Hector

[MyPrevost]

Adam,

Any words of wisdom on what to do or what not to do when changing our a Wabasto blower motor?

Hector

What exchanger/blower do you have? As I understand it, there are two options: The Red Dot and the Frigid Cool. The distinguishing factor between them? The Frigid Cool has a double squirrel cage fan with the motor in between them. (That’s what I have.) The red dot one is the one pictured on Mango’s page.

I’ll try to take pictures as I change mine.

~A

[MyPrevost]

Get some of those tools that clamp the hoses without crimping them. I found them at Napa and even a cheap one at Pep Boys.

Be careful, you can lose a LOT of coolant quickly, and it’s a mess. I found this removing the guts of the valves back in my webasto compartment.

Ray

[MyPrevost]

Get some of those tools that clamp the hoses without crimping them. I found them at Napa and even a cheap one at Pep Boys.

Be careful, you can lose a LOT of coolant quickly, and it’s a mess. I found this removing the guts of the valves back in my webasto compartment.

Ray

Got ’em! Though I’m thinking I can do this without removing the hoses. Will let you know.

Thanks Ray!

Adam

[MyPrevost]

OK, it’s done. Thanks to all you guys… and a special thanks to Jim Shoen who called today with a few “been there, done that” details. For posterity…. if you should have a frigid cool heat exchanger fan go bad…

First, you know it is a frigid cool if it has a double squirrel cage fan. If this is not the case, Mango’s post on Prevoman is the one you should be reading.

Remove the dash cover.

the fan/motor assembly is inside of a sheet metal cabinet. At first glance, it looks like it “wraps around” from front to back. But it does not. The front face and half of the top side are one, bent, 90 degree piece. The fan/motor assembly is bolted to this. So, unscrew the small screws on the front face and on the top side. Then the whole assembly just “falls” out. Wires and are easy to disconnect. Very obvious.

One point I should mention… to get to all the little screws, I had to be able to move the whole exchanger unit around a little bit. It was attached to the prevost dash air below it (pictured in Mango’s post) and I was simply able to unhook two, very obvious brackets, and a few hidden screws. (Good job Marathon!)

Ok, back to the fan/motor assembly. Once out, all that is left in the dash is the heat exchanger/radiator. Leave that there.

Then, it was a little bit annoying after that… lots of little screws and bolts to undo to get to the fan/motor assembly. It was encased in a sound absorbing, foam sleeve/bracket, but that bracket was attached to the sheet metal case. No big deal, but the screw heads were on the sheet meal side. If they had just put them on the other side, it would have saved 10 minutes and a lot of hassle detaching the mount from the metal. At this point, everything was very obvious. Thanks to Jim, I knew to look for the two spring clips that were keeping the squirrel cages attached to the motor shafts. Easy enough to remove with pliers. I measured the distance, end to end, of the two cages before I took them off. Made for a really easy reassembly. I should have also noted the direction that the cages needed to be reattached. That was a little confusing… until I saw the arrows on the cages and matched them to the arrows on the motor. Duh! But still, I should have thought of that before I took them off the original shaft. But I was a little distracted by the fact that they were delicate plastic and were kind of hard to get off without muscle…. which, since I’m only 35 I still have plenty of. You older guys probably don’t have to worry about breaking anything though 🙂

At this point, things moved fast. Made a couple of simple modifications upon reassembly to make things faster should I have to do this again. (Put screws heads on the accessible side so I wouldn’t have to detach the motor bracket from the sheet metal again. Had to clip the black wire end off and put on a wire nut, connecting it to the white wire. (you’ll know what I mean if you tackle this project.) Replaced everything where it was before I got into it all. About 90 minutes later, I was done, tools were away, and here I am typing with warm air blowing on my feet. Nice. But, as Jim said on the phone today… yet another job that should take only about 10 minutes, but that ended up taking 10 times that!

Oh, one thing I did, inspired by Jon’s frequent mention of “bench testing.” Once removed, I hooked the old motor back up to the dash wiring. Sure enough, it didn’t run. Did the same thing with the new motor and it fired right up. Was glad I did this. Could you imagine, doing the whole project and then realizing it was something else? Next time, I would bench test the new one before I even took the old one out. Just to be sure.

Last, but not least… part numbers. Marathon had this item drop shipped for me and over nighted to me on the road. So, all I have is their number system. “Item # 102256 | 01 Motor Only for H20 Heater $110.51” (by the way, that vertical line between the numbers is just that… a line. Not a back slash or a number. Not sure if it is integral to the part number.

$20 to ship it overnight. $131 later, I’m warm and ready to tackle by battery issue.

Thanks for the help guys. If anybody gets into this project and needs to talk, feel free to call anytime. 304-667-4501.

~Adam

[MyPrevost]

Adam,

Great job. Perhaps better than buried in a thread that we’ll lose in the future, how do we go about getting this written as an article and posted to the articles area?

Ray

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