Maybe somebody can give me some advice.
I've got an older duotherm roofair. I have no clue what the BTU rating is on it and couldn't find a tag with that listed BTU or a model number.
The squirrel cage fan in it is going out. Is this fan difficult to repair or replace? Can the motor in the fan be rebuilt?
And if replacement is needed, where should I look to find the model number for finding the part.
And lastly, where would the best place to buy the part be?
Considering you can buy a new one for about $600-how much of your time are you going to spend on this? Personally, I wouldn't spend the time on an old unit-fix one thing and another goes, etc. New ones are more powerful, quiet, and reliable. Good Luck, TomC
Hello Art,
The older Duotherm units are no different then the new ones. The blower motors are a doubble shafted and require
removing the evap compartment and the condencer shroud. Please note that the shafts will be Rusty! So removing them
requires hack sawing the shafts and then using a press to remove them from the fan hub. This job is better done on the ground
and not on the roof of your bus! Just to let you know, Dometic Corp. always sends us a whole new unit if the fan motor goes
bad within the 3 year warranty coverage. Maybe they don't want to pay all the labor expence!
Good Luck
Nick-
Thanks for the replies. A replacement unit is probably in order. It's a shame though because the unit works great when the fan turns. Sometimes it just won't spin up. Most times (when it refuses to start), taking off the inside unit, turning the fan by hand, and then putting power back to the unit will allow the a/c to start. Last night it would not start even after turning the fan by hand. It was a bit stiffer than usual.
I'll probably pull the old one apart for the sake of knowledge.
I was told that lubricating the shaft might prolong the unit's life a while longer.
I'm doubtful because the shaft is fairly stiff turning. I'm thinking it's most likely a rusty shaft.
Even so, the only way I could see to do anything about that rust would be to disassemble the entire unit.
Then I have to factor in the fact that I'm NOT knowledgeable (DKS) with these units. I'm guessing there are bearings in the motor which are most likely shot as well.
The only experience I've had with electrical motors were large ones turning pumps in a coin-op car wash.
These were rebuilt repeatedly but were always taken to a professional for the work.
If you have a rusting problem-like living near the ocean shore, Coleman makes marine roof airs with stainless shafts, etc to with stand the salty environment. Good Luck, TomC
Try squirting some spray lubricant on the shaft where it enters the motor and then get the motor running. If possible squirt some spray lubricant while the motor is running. Enough should get in to lubricate the bushings and/or bearings.
Richard
If you try lubricating it use PB Blaster it is the best penetrating oil that I have used.
Thanks guys.
I know that a new unit is only around $600-$700 but right this minute the money could be used elsewhere.
If lubricating it would make it last even a couple more months, it would help a lot.
I'd like a bigger unit, possibly even a heat pump. If I have to buy immediately, I'd be stuck going for what I have cash on hand for. I'd rather get what is the proper solution for my setup without regard to price.
Half of the fun for some of us is getting what we have working again. I have two Durotherms that were manufactured in 1979. When I got my bus I had little hope that they would work, especially after seeing the condenser on one and the wiring in both. All I had to do was charge up one unit (I did it myself and it was on the one with the nice condenser) and make some new filters. On our trip to the beach, we left them on all day and all night, and they worked great. The build plate on mine is located on the top right of the condenser. The more I can do myself (granted much of it is out of necessity and lack of funds) the more my confidence grows. It's a great feeling. Try the lube, and if that doesn't work, do the motor swap. I like PB blaster also, but my favorite is Marvels Mystery Oil. While in high school I worked in a machine shop that used that stuff for everything. Not only did it do a great job of penetrating (if allowed to sit overnight), it has some very good and lasting lubricating properties. Keep us posted on your progress.
Now I just have to figure out what the best way to get in there to lubricate will be.
I'll have to take a closer look at the unit when I get home from work.
Give me some resin, reinforcement, wood, foam, or other assorted things to build a form and I can make pretty nice composite (fiberglass) parts. Stuff like this and I'll have to stumble with it a bit.
Hi Art,
To access the fan motor on all of the roof airs that I have worked on you need to remove the OUTSIDE cover and the motor is right in the open. I am like Barn Owl, I like to see if I can fix something before throwing money at the problem. Even if lubricating the shaft bearings/bushings doesn't cure the problem a new motor shouldn't cost too much. If you do need a new motor, I would take the motor with fans still attached to an electric motor repair shop and have them test it. It is likely they can provide a replacement motor even if it isn't the same brand. As a last resort you could call Duotherm for a new motor. I have a scaffold that I set up next to the bus and I lay a plank from it to the roof for easy access. Good luck with the project and be careful working on the roof. Sam 4106
ok, I got the outside cover off of the roofair. Somebody really messed up the screws holding it on.
I lubricated the shaft on the motor and it it spins nicely now.
I think it's burnt up now though. When you turn the unit on, you can see the shaft try to turn but never starts.
I stopped taking it apart before the motor was completly free from the unit. I wasn't quite sure how to finish taking it out. It looked like I had to remove an allen set screw from a retainer for the squirrel cage fan. This should give access to the screws holding the motor in. I didn't have the correct allen wrench at the time so I called it a night. A new unit is looking better though.
If it turns freely but won't start, it may just need a capacitor.
Len
Quote from: Len Silva on July 18, 2007, 01:40:48 PM
If it turns freely but won't start, it may just need a capacitor.
Len
I remember seeing that Dallas had 1 of those in another post! LOL!
;D BK ;D
Quote from: Busted Knuckle on July 18, 2007, 03:33:59 PM
Quote from: Len Silva on July 18, 2007, 01:40:48 PM
If it turns freely but won't start, it may just need a capacitor.
Len
I remember seeing that Dallas had 1 of those in another post! LOL!
;D BK ;D
Yup,
Here it Are:
Don't buy it, that one is shot! ;)
HI
Here's an excellent resource for almost all the Duro-Term manuals
This is one of the Clasic GMC MotorHome technical repositories(sp??)
see--> http://www.bdub.net/manuals/index.html
Pete RTS/Daytona (X-GMC M/H'er) -- I now have it's Big Little Brother - an RTS Bus Conversion)
Dallas,
That capacitor is fake.....
This is the real "Flux Capacitor" that runs my A/C's in my bus.
I stole it out of an old Delorean I found in a junk yard...
Nick-
sorry Nick that is one of the older models
Look for the one with the Quisenart :)
Skip
Darn.....
And I thought I had the Art of the State, Notch Top, Radio Transistor!
Well Oh!
Nick-
Nick
You're still ahead of me I'm still counting colored bands on a brown backround. sorry I couldn't resist
Next year I hope to learn to read capacitors.
Skip
I found new motors for the unit for around $105.
Was I right in assuming that the allen set screw will release the squirrel cage to allow access to remove the motor?
Anyone else agree that it might be the capacitor that's shot and might need replacement and not the motor? After lubricating the shaft it definitely turns easily.
Capacitors are very easy to check and if they do fail, they are inexpensive. Do that first.
Quote from: ArtMaybee on July 19, 2007, 07:28:34 AM
I found new motors for the unit for around $105.
Was I right in assuming that the allen set screw will release the squirrel cage to allow access to remove the motor?
Anyone else agree that it might be the capacitor that's shot and might need replacement and not the motor? After lubricating the shaft it definitely turns easily.
Hi Art,
If all else is in working order on the unit then I would opt to put the motor in.
You are one allen screw away from removing it anyway. If would be kinda foolish not to .
Good Luck
Nick-
Sure sounds like the starting capacitor. I would try one first before removing the motor assembly.
Unfortunately if you replace the motor and the capacitor is bad, then it still will not run. Capacitors are cheap compared to a motor.
Richard
Quote from: DrivingMissLazy
Sure sounds like the starting capacitor. I would try one first before removing the motor assembly.
Unfortunately if you replace the motor and the capacitor is bad, then it still will not run. Capacitors are cheap compared to a motor.
Richard
Richard I'm thinking that Nick is saying if a new motor is only $ 105.00 he'd go ahead and replace it as well as a bad capacitor (if the capacitor is bad!). And I have to agree with Nick, if all else is good and you've got it tore down that far why not add a few more yrs worth of insurance that it won't need a motor this time next yr! At least that's the way I interpreted Nick! And also what I would do! FWIW
;D BK ;D
I have no problem with replacing the motor if it is needed.
I just like to
definitely isolate a problem first as to what is actually bad before I start arbitrarily replacing components. Many times lubricating the bushings/bearings allows a motor to run for a long time with no further action required. Just my way of troubleshooting and doing things. Others may do it differently and that is fine.
Richard
Quote from: Busted Knuckle on July 19, 2007, 04:13:54 PM
Quote from: DrivingMissLazy
Sure sounds like the starting capacitor. I would try one first before removing the motor assembly.
Unfortunately if you replace the motor and the capacitor is bad, then it still will not run. Capacitors are cheap compared to a motor.
Richard
Richard I'm thinking that Nick is saying if a new motor is only $ 105.00 he'd go ahead and replace it as well as a bad capacitor (if the capacitor is bad!). And I have to agree with Nick, if all else is good and you've got it tore down that far why not add a few more yrs worth of insurance that it won't need a motor this time next yr! At least that's the way I interpreted Nick! And also what I would do! FWIW
;D BK ;D
I guess I didn't spell it out clear enough! I should have said
"go ahead and test the capacitor and then if it is bad. I'd replace it and the motor since it's tore down that far!Quote from: DrivingMissLazy
I have no problem with replacing the motor if it is needed.
I just like to definitely isolate a problem first as to what is actually bad before I start arbitrarily replacing components.
Richard
I agree 100%Quote from: Busted Knuckle
Quote from: DrivingMissLazy
Sure sounds like the starting capacitor. I would try one first before removing the motor assembly.
Unfortunately if you replace the motor and the capacitor is bad, then it still will not run. Capacitors are cheap compared to a motor.
Richard
Richard I'm thinking that Nick is saying if a new motor is only $ 105.00 he'd go ahead and replace it as well as a bad capacitor (if the capacitor is bad!). And I have to agree with Nick, if all else is good and you've got it tore down that far why not add a few more yrs worth of insurance that it won't need a motor this time next yr! At least that's the way I interpreted Nick! And also what I would do! FWIW
;D BK ;D
;D BK ;D
I can agree with that with no problem. Especially if he already has the motor. Otherwise I suspect I would save the $105 to put on something else. LOL
Richard
Quote from: Busted Knuckle on July 19, 2007, 04:29:57 PM
I guess I didn't spell it out clear enough! I should have said "go ahead and test the capacitor and then if it is bad. I'd replace it and the motor since it's tore down that far!
Quote from: DrivingMissLazy
I have no problem with replacing the motor if it is needed.
I just like to definitely isolate a problem first as to what is actually bad before I start arbitrarily replacing components.
Richard
I agree 100%
Quote from: Busted Knuckle
Quote from: DrivingMissLazy
Sure sounds like the starting capacitor. I would try one first before removing the motor assembly.
Unfortunately if you replace the motor and the capacitor is bad, then it still will not run. Capacitors are cheap compared to a motor.
Richard
Richard I'm thinking that Nick is saying if a new motor is only $ 105.00 he'd go ahead and replace it as well as a bad capacitor (if the capacitor is bad!). And I have to agree with Nick, if all else is good and you've got it tore down that far why not add a few more yrs worth of insurance that it won't need a motor this time next yr! At least that's the way I interpreted Nick! And also what I would do! FWIW
;D BK ;D
;D BK ;D
Capacitors go bad more often than you might think. You can test capacitors with your multi-meter. Many multi-meters have the ability to easily test them built in. Do an internet search on how to test capacitors and test before you spend $105. I agree with Richard, use the money somewhere else if you don't need a motor.
Looks like just what you are looking for. eBay item 330148408129
Len
I will definitely check out the capacitor first.
$105 isn't that much to spend but.... It's really not that hard to break down the A/C to the point I'm at.
The only issue I had was stripped out screws on the housing.
Does anyone know if the motor listed in that ebay ad will fit my older unit?
What about newer outer housings... Can I used the newer housing on my older A/C unit?
The one I have has a bit of age and it would be nice to clean it up a bit with a new housing.
First of all, let me state that I come from the old school of diagnose the problem and repair the problem, not the current thinking of just replace the black box, regardless of what the internal problem is.
If I were doing it, the first thing I would do would determine if the capacitor is bad. If it is, replace it. Since the shaft was hard to turn before you lubed it, I would then pull the fan motor and replace the bearings. Probably all of $10. in parts. Then re-assemble the unit and run it for another ten years.
Richard
I can't count all the locked up small elect motor shafts I've tried oiling over the years in hopes that it would be ok. I've never had one that worked more than a short time before it locked up again. One would think that I would learn but so far I keep hoping!!
It appears to me that the shaft scores before it locks up and the oil will not fix that. If it isn't scored it is usually rusted, either way the shaft bushing gets damaged permanently.
I agree with you.
I've just got to look up the procedure for testing the capacitor.
I don't like to replace anything that doesn't have to be replaced. unless it's something like a waterpump, clutch assembly, etc that would cost a LOT of time and or money to replace at a later date if it fails.
It took all of 10 minutes to disassemle the A/C unit so I can live with pulling it back apart if the motor fails.
I was thinking that removing the shaft from the motor might be beyond my available tool resources.
I thought I saw mention of having to press the shaft out. And I'd be worried about bending the shaft trying to monkey it out incorrectly.
Hi Art,
Sometimes the shaft is so rusted that it is better done by cutting the shaft, sanding the rust, then place the hub on a press to remove the old shaft.
Just look at the shaft on yours. You can even try and sand it, if it sands up smooth, you most likely will be able to slide the hub right off. But if it's very
pitted with rust, it may be a little harder to remove the hub.
Good Luck
Nick-