# ECM Blower Motor bad



## Dragons Den (Feb 11, 2011)

Hey all, first time poster. 

Recently my blower motor burnt up on a 3 ton Coleman self contained heat pump AC unit according to the HVAC company that came out. They want $1100 to replace it and after calling around i've found similar prices by their competitors, the cheapest being about $700 for a new motor. I unfortunately don't have that kind of cash just laying around, especially in this economy SO i'm stuck fixing it myself. That part isn't the problem, the problem is i'm looking for a different type of motor to swap it with so i'm here to ask for advice. 

The bad motor is a G.E. brand ECM 2.3 motor, 220 volts and 3/4HP. 

My first question would be could I swap it with a Direct Drive blower motor, split capacitor at 3/4HP, 208-230 volt model if I put in a relay? My buddy has an account at Grainger and that seems to be the only models they sell for blower motors. 

If not what kind of motor CAN I swap it out with? 

Any help anyone could provide would be appreciated. Thanks in advance!


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## yuri (Nov 29, 2008)

You need the ECM motor as it is a variable speed motor and the circuit board in your unit needs to control it and set the speeds for the different functions of your unit. Basic PSC motors are 4 fixed speeds and are not compatible with the logic circuit in your control board and there is no simple add a relay fix. If the speed is incorrect you won't get proper heat or cooling from the unit and could damage the compressor.


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## Marty S. (Oct 31, 2009)

Google zebra ecm motor repair kit. I have not used it but heard it works to fix many of them.


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## Dragons Den (Feb 11, 2011)

yuri said:


> You need the ECM motor as it is a variable speed motor and the circuit board in your unit needs to control it and set the speeds for the different functions of your unit. Basic PSC motors are 4 fixed speeds and are not compatible with the logic circuit in your control board and there is no simple add a relay fix. If the speed is incorrect you won't get proper heat or cooling from the unit and could damage the compressor.


Well I can't afford a new ECM Motor so unless there's some other way i'll just have no heat or AC for the next few years. Thanks anyways.


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## Dragons Den (Feb 11, 2011)

Marty S. said:


> Google zebra ecm motor repair kit. I have not used it but heard it works to fix many of them.



Will look into that, thanks.


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## beenthere (Oct 11, 2008)

Check your warranty, good chance that motor is still under warranty.


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## bob22 (May 28, 2008)

Might try looking at these threads:
http://www.diychatroom.com/f17/carrier-hi-90-furnance-variable-speed-motor-89865/
for related info.


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## hvaclover (Oct 2, 2008)

yuri said:


> You need the ECM motor as it is a variable speed motor and the circuit board in your unit needs to control it and set the speeds for the different functions of your unit. Basic PSC motors are 4 fixed speeds and are not compatible with the logic circuit in your control board and there is no simple add a relay fix. If the speed is incorrect you won't get proper heat or cooling from the unit and could damage the compressor.


That is necessarily always the case.

On the equipment I sell the ECM motor can be replaced with a standard motor and the board even has terminal for a PSC motor hook up.

I always say "never say never".

Post your make and model with a wiring diagram if possible and we or I will get your heat back on.


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## beenthere (Oct 11, 2008)

hvaclover said:


> That is necessarily always the case.
> 
> On the equipment I sell the ECM motor can be replaced with a standard motor and the board even has terminal for a PSC motor hook up.
> 
> ...


A PSC can be installed in that Coleman. He'll lose some performance as with any unit that it is done to. 

Doubt the motor is bad, the module probably, which is much cheaper then an entire motor.

But it should be under warranty.


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## Dragons Den (Feb 11, 2011)

hvaclover said:


> That is necessarily always the case.
> 
> On the equipment I sell the ECM motor can be replaced with a standard motor and the board even has terminal for a PSC motor hook up.
> 
> ...



Thanks for the reply! The motor is a G.E. ECM 2.3, Model: 5SME395L 3/4HP, 120/240V. The AC unit is a Coleman model: BBUP-F042AA. I'm not sure about the diagram, it has a plug in on the motor that the wires are connected to. 

A little extra info if it helps is the condenser motor connects to a run capacitor as well as a relay, the blower motor doesn't.


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## Dragons Den (Feb 11, 2011)

beenthere said:


> A PSC can be installed in that Coleman. He'll lose some performance as with any unit that it is done to.
> 
> Doubt the motor is bad, the module probably, which is much cheaper then an entire motor.
> 
> But it should be under warranty.


You're correct, it looks like it may be the thermistor in the module, it IS burnt up. I bench checked the motor and am getting good ohms(5.8 across the board) and the shaft turns HOWEVER there is one little jerk on it when I rotate it and it makes a feint grinding noise so i'm not 100% certain. 

As for the warranty I checked around and consensus is I have to go through a licensed contractor, they won't just take the motor back from me and send me a new one. That would be fine if these local companies were reasonable. Some want the money up front then if it's warrantied they will reimburse me motor cost. Others are willing to check first then just charge labor. That sounds fair except the quoted prices range from $500-$700 in labor charges to swap it out. Again I don't have that kind of money and it honestly seems a little steep to me. Maybe it sounds fair but it took me 10 minutes to remove the motor and the service tech I had out said if I could find a deal on a new ECM all I have to do is unplug and remove the bad one, slide the new one in, tighten the three bolts on the strap and plug it in. 

I'm not trying to offend and I understand having to buy gas and tools, having to learn your craft(i'm a tradesman as well) and invest money into it but $500 sounds like alot of money for about 30 minutes worth of work.


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## hvaclover (Oct 2, 2008)

Dragons Den said:


> You're correct, it looks like it may be the thermistor in the module, it IS burnt up. I bench checked the motor and am getting good ohms(5.8 across the board) and the shaft turns HOWEVER there is one little jerk on it when I rotate it and it makes a feint grinding noise so i'm not 100% certain.
> 
> As for the warranty I checked around and consensus is I have to go through a licensed contractor, they won't just take the motor back from me and send me a new one. That would be fine if these local companies were reasonable. Some want the money up front then if it's warrantied they will reimburse me motor cost. Others are willing to check first then just charge labor. That sounds fair except the quoted prices range from $500-$700 in labor charges to swap it out. Again I don't have that kind of money and it honestly seems a little steep to me. Maybe it sounds fair but it took me 10 minutes to remove the motor and the service tech I had out said if I could find a deal on a new ECM all I have to do is unplug and remove the bad one, slide the new one in, tighten the three bolts on the strap and plug it in.
> 
> I'm not trying to offend and I understand having to buy gas and tools, having to learn your craft(i'm a tradesman as well) and invest money into it but $500 sounds like alot of money for about 30 minutes worth of work.


That can be replaced and there is a part number and pacle to buy it in this forum a while back.

I don not condone the repair but for the sake of honesty it can be done. I don't reccommend it...there,,, that ought to make my liability carrier happy.:whistling2:


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## beenthere (Oct 11, 2008)

Plus, you still need to fix the poor air flow of your duct system. Since thats what took out the module.


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## hvaclover (Oct 2, 2008)

beenthere said:


> Plus, you still need to fix the poor air flow of your duct system. Since thats what took out the module.


 i don't think your liability carrier is worried about udersize duct work







Ok...that joke sucked....I'm off my game


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## beenthere (Oct 11, 2008)

hvaclover said:


> i don't think your liability carrier is worried about udersize duct work
> 
> 
> 
> ...


He ain't worried about my comment on forums either. :laughing:


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## Dragons Den (Feb 11, 2011)

beenthere said:


> Plus, you still need to fix the poor air flow of your duct system. Since thats what took out the module.


Good point. If I may ask what are some things to look for to determine the cause of the poor airflow aside from the filter which I change regularly? Thanks in advance and thanks for your help so far! :thumbsup:


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## beenthere (Oct 11, 2008)

The duct system itself. Post the sizes of your return an d supply ducts. They are most likely too small. Could also have crushed duct work, or kinks in the duct.

What size unit was there before the Coleman.


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## diyorpay (Sep 21, 2010)

Most interesting relevant post about variable speed fans. Worth a look:

http://www.diychatroom.com/f17/carrier-58mvp-blower-problem-9939/


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## Dragons Den (Feb 11, 2011)

beenthere said:


> The duct system itself. Post the sizes of your return an d supply ducts. They are most likely too small. Could also have crushed duct work, or kinks in the duct.
> 
> What size unit was there before the Coleman.



16". That all checked out when I went from a 1T to 3T A/C Unit. I had an electrician buddy of mine come out and the breaker for the A/C unit was going bad, think maybe that fried the thermistor?

To update: I finally received the new thermistor three days ago and soldered it in and tried the fan motor. While it now will turn on it slows and speeds repeatedly every few seconds so it's probably bad. I bought a PSC motor and am just going to go that route.


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## beenthere (Oct 11, 2008)

The slowing and speeding up is from under sized, restricted duct, or too many closed or covered up registers/grilles.

A single 16" flex duct is border line for 3 tons. A static pressure test will tell you how bad your duct work is or isn't.


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## wyoming (Nov 23, 2013)

My ECM motor was making horrible noises. It was still working but the house was taking 3 times as long to heat up. I took the ECM out and took off the back plate and noticed a ton of dust. Like my computer I blew off all the dust and it resumed working. I believe the electronics were confused by all the dust. I later saw in the manuel that every year I am supposed to vacume it out once a year. 

I hope that helps someone. 

I also had a small water leak and tightened my condensation tubes
then I had and no more leak. 

Thanks to all the other posts (from other sites too) this gave me all these ideas so I didn't have to make call to the repairman. I hope this helps someone.


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## sammyy125 (Jan 5, 2014)

*hvac thermistor 379 replacement*

I have a bunch of SG405 thermistors that replace Sg379 Thermistors
I sell them for ten bucks a piece call 800-584-1892 leave a message I I will 
send one to you for 10.00 plus the price of a stamp.


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